CA1340649C - Purified follicle stimulating hormone - Google Patents

Abstract

Purification of human follicle stimulating hormone from post-menopausal urine gonadotropin using immunochromatography and reverse-phase HPLC steps yields a biologically active hormone which is free from detectable traces of LH and other urinary proteins and has a specific follicle stimulating hormone (FSH) activity of not less than 6,200 I.U. of FSH per mg of lyophilized powder.

Description

.~~~~Jb~9 PURIFIED FOLLICLE STIMULATING HORMONE
Field of the invention This invention relates to follicle stimulating hormone, to pharmaceutical compositions containing it and to a method for its purification.
Background of the invention Follicle stimulating hormone (FSH) is known to be useful in the treat-ment of infertility. Preparations containing this hormone have been employed to assist in effecting pregnancy using both in-vivo and in-vitro techniques. Human FS~i has been isolated from human pituitary glands and from post-menopausal urine. More recently, it has been pro-duced using recombinant DNA techniques.
The first commercially available product comprising human FSH contained HMG (e. g., Pergonal(R) Serono), i.e., human menopausal gonadotropin extracted from post-menopausal urine which is a mixture of FSH, Lutein-izing Hormone (LH) and other urinary proteins. Meanwhile, several attempts were made to obtain pure FSH preparations, both for scientific and therapeutic purposes. The product Metrodin(R) (Serono), currently available in commerce, is a preparation of urinary FSH containing other urinary proteins, but minimum quantities of LH and is used for the treatment of infertility. Use of this product is particularly advanta-geous when administration of exogenous LH together with FSH is undesir-able, e.g., in the polycystic ovary syndrome (PAS).
So far, administration of FSH for therapeutic purposes has been carried out, successfully, exclusively by intramuscular injection. Since intramuscular injections are generally performed by the physician or by the medical professional staff, the patient is expected to visit a surgery or a hospital regularly in order to receive the treatment.
'Ibis crEates a considerable discomfort. Moreover, the time taken up by this type of application often leads to unsatisfactory compliance by the petient as the treatment normally extends over several weeks or months.
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13~0~4~

Administration by subcutaneous injection would render possible the self-administration by the patient and consequently improve patient's cooperation and compliance.
The subcutaneous administration of Human Menopausal Gonado-tropin (HMG) has already been described (Nakamura Y. et al., Fertility and Sterility, 46(1):46-54, 1986) in connection with the treatment of female infertility by pulsatile administration of HMG via the subcutaneous peristaltic pump. The sub-cutaneous administration may suffer the drawback of the appearance of local allergies due to the presence of impurities in the product used and, consequently, result in the suspension of the treatment.
P. Roos ("Human Follicle Stimulating Hormone", Acta Endocrinologica Supplementum 131, 1968) described and characterized highly purified preparations of pituitary and urinary FSH obtained from frozen pituit-aries and from post-menopausal urinary concentrate, respectively. Bio-logical potencies as high as about 14,000 I.U. of FSH activity per m3 for pituitary FSH and 780 I.U. of FSH activity per mg for urinary FSH
were obtained. The content of LH contamination in the most active pituitary and urinary preparations was estimated to correspond to approximately 0.1 per cent by weight. The purification procedures in-volved one or more of such techniques as chromatography on DEAF-Cellu-lose, gel-filtration on Sephadex G-100, hydroxylapatite chromatography, polyacrylamide gel electrophoresis, and the like.
One of the best purified urinary FSH preparations was described by Donini et al. ("Purification and partial Chemico-physical character-ization of FSH from Menopausal Urine", Gonadotrophins and Ovarian Development (Proceedings of two workshop meetings), E and S Living-stone, Edinburgh and London, 1970) and had a biological potency of 1255.6 I.U. FSH per mg with an LH contamination as low as 3.2 I.U. LH
per mg.. In this case, the starting material was a Human Menopausal Gonadotropin (HIS) preparation (Pergonal(R)) which, as stated above, is a mixture of FSH and LH hormones and other urinary proteins. This - 3 - :I340b49 result was achieved by batchwise purification of the starting I~ on DEAE~ellulose followed by chromatography on a DEAF-Cellulose column, gel filtration on Sephadex~G-100 and a final step of preparative poly-acrylamide gel electrophoresis.
Even higher biological potencies were achieved by H. Van Hell et al.
("Purification and some properties of human urinary FSH and LH", Gonadotropins (Proceedings of Int.l Symposium on Gonadotropins, 1971), Wiley - Interscience, New York) by adding immunochromatography and gel-filtration steps to a conventional chromatographic purification procedure. Irnnunochromatography was performed using anti-HCG anti-bodies coupled to Sepharose~ for the specific purpose of removing the LH activity from partially purified FSH fractions. ~e best purified FSH fraction contained 4720 I.U. FSH per mg and the LH contamination was as low as 15 I.U. LH per mg as assayed by RIA.
The immunochromatographic approach had already been described by Doni-ni et a1. ("Purification and Separation of FSH and LH from HMG", Acta Endocrinoloqica 52, pages 186-198, 1966) who obtained as early as 1966 an FSH preparation which had a potency of 329.7 I.U. FSH per mg and biologically undetectable amounts of LH contamination. In another experiment, a fraction assaying 148.3 I.U. FSH per mg and 2.4 I.U. LH
per mg was obtained. Since no RIA was performed on the 329.7 I.U. FSH
per mg preparation, it can be assumed by analogy with the results of H. Van Hell (c.f. supra) that traces of LH would have been found if assayed by RIA.
The physiological relevance of even minimal amounts of LH contamination was shown by Donini et al. in a paper ("A new approach to the Biologic-al Determination of the Luteinizing Hormone", Acta Endocrinologica, 58, pages 463-472, 1968) where a new bio-assay for LH determination was proposed which consisted in 'injecting intact immature mice with a constant dose of a biologically pure FSH preparation plus increasing amounts of LH and then measuring the increase in the uterine weight as *Trademark i:. .~

_4_ 134Q6~9 a response proportional to the LH activity. By this method, as little as 0.068 I.U. of LH were shown to be capable of increasing the uterine weight when injected together with 4.44 I.U. of FSH.
It thus clearly follows that an absolutely pure FSH preparation is desirable when FSH activity in the complete absence of Iii activity is requested in therapy.
As mentioned above, the currently marketed product Metrodin(R) (Se-rono) is a purified FSH preparation which is obtained by a method substantially identical to that described by Donini et al. in an al-ready mentioned paper (Acta Endocrinologica 52, pages 186-198, 1966).
the quality control specifications, in agreement with the declared bio-logical purity of the said preparation, provide for not more than 0.7 I.U. LH per 75 I.U. of FSH, i.e., approximately the sensitivity limit of the biological assay. In certain therapeutic applications, however, the absolute absence of LH is desirable. El~rthermore, in Metrodin(R), human FSH is accompanied by substantial amounts of other urinary proteins, i.e., it is not a chemically pure FSH preparation.
U.K. patent application 2,173,803 A provides still another approach to the purification of pituitary glycoprotein hormones, among them FSH.
This approach consists of first forming a complex of the hormone with immobilized monoclonal antibodies and then eluting the hormone with an acidic aqueous buffer having a pH from 3 to 4. As far as FSH is con-cerned, the obtained highly purified hormone is still contaminated with 0.1~ by weight of LH and 0.5~ by weight of TSH.
Scott C. Chappel et al. describe in a review article (Endocrine Reviews 4(2), 179-211, 1983) the microheterogeneity of FSH and the physiologic-al significance of the carbohydrate moieties accompanying the FSH
molecule. Zhe hypothesis can be formulatt~d that some modifications occur during the metabolic pathway up to the final urinary secretion which may account for the chemico-physical 3ifferentiation demonstrated 1340~~
in the experiments carried out by Applicant between the highly purified urinary FSH preparation (hpuFSH) according to this invention, and the highly purified pituitary FSH preparation used for comparison purposes.
Co- or post-translationally modifications appear to be the basis for microheterogenous diversity of FSH, a glycoprotein consisting of two dissimilar, glycosylated, non covalently linked polypeptide chains known as alpha and beta-subunit. Zhe beta-subunit endows the molecule with its biological specifity.
Incidentally, the same article attempts to explain the substantial difference in the values of biological activity per mg between highly purified pituitary and urinary FSH preparations. A reasonable hypothes-is can again be based on the relevance of the carbohydrate moieties and, more specifically, the role of the terminal sialic acid residues.
It should be noted that, while both pituitary FSH and urinary FSH are termed "FSH", no conclusive evidence has yet been found which verifies whether the molecules isolated from the two sources are the same or even chemically equivalent.
Description of the invention It has now been found trat FSH can be isolated from a concentrate of post-menopausal urine to such a degree of purity that the resultant FSH is completely free from any detectable traces of LH and other urinary proteins.
Furthermore and contrary to any expectation, the amino acid analysis of the urinary FSH according to the present invention has revealed a novel FSH beta-subunit of 111 amino acids instead of 118 or 108 as reported in the state of the art (see e.g..Scott et al. supra) for the known FSH beta-subunit.
More specifically, this invention provides a protein comprising an a- and 13-subunit, wherein the a-subunit is a gonadotropin a-subunit and the f~-subunit has the following amino acid sequence:

134(J~~9 Asn Cps Leu Thr IleThr Ile Ala Ile LysGlu CysArg Ser Glu Asn Glu Glu Phe Ile Ile Asn ThrTrp Gys Ala Gly CysTyr ArgAsp Cys Ser Thr Tyr 'Ii~r Leu Tyr Asp Pro ArgPro Lys Ile Gln ThrCys PheLys Ual Lys Ala Lys Zhr Glu Ual Glu Thr ArgUal Pro Gly Cps HisHis AspSer Leu Tyr Ual Ala Ala Leu Zhr Pro Ual ThrGln Cys His Cps LysCps SerAsp Tyr Tyr Ala Gly Asp Ser Asp Thr Ual GlyLeu Gly Pro Ser CysSer GlyGlu ~r Cps Arg Tyr Phe Met Glu Lys the protein having a specific follicle stimulating hormone (FSH) activity of not less than 6,200 I.U. of FSH per mg of lyophilized powder and being substantially free from detectable traces of luteinizing hormone (LH) and other urinary proteins.
A further aspect of the invention is a pharmaceutical composition containing a purified protein according to the present invention and a pharmaceutically acceptable excipient. Preferably the composition is in a form suitable for subcutaneous administration. It has been found that subcutaneous injection of a pharmaceutical composition according to the present invention does not give rise to the appearance of those allergical reactions normally encountered with the known FSH prepara-tions.
According to a further aspect of this invention, a method is provided to produce the novel and highly purified FSH according to the present application. The method is substantially based on the combination of an immunopurification step with reverse phase HPLC. The immunopurifica-tion step uses immobilized monoclonal antibodies substantially as described in the above mentioned U.K. patent application 2,173,803A, but with the fundamental difference that elution of FSH from the imnunocomplex is carried out at much higher pH values.
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~~~oo~o . ,. _ 7 -In the process of the present invention elution is conveniently carried out using an aqueous solution having a pH
higher than about 10 and a molarity higher than about 0.5. The experiments carried out by Applicant have shown that, in these conditions the immobilized antibody is not substantially inactivated. This is in contrast with the teaching of the above mentioned U.K. patent application which states (on page 1, lines 36 - 37) that "the use of eluents having such high pHs is not feasible in practice since it leads to rapid inactivation of the antibody".
This difference in behaviour may depend upon differences in the methods adopted to link the antibody to the resin.
According to this invention, the pH of the eluent is preferably higher than 11 and more preferably comprised within the range of 11.3 to 11.7.
Molarity values are preferably higher than 0.8 and more preferably of about 1.
Suitable eluents for use in the invention process are ammonia, diethylamine and such buffers as TRIS buffer, glycine-NaOH and the like.
The subsequent reverse phase high pressure liquid chromatography (HPLC) step permits one to obtain the complete removal of any contaminating proteins. This removal is not achieved by the immuno-purification step alone, as is also acknowledged in the U.K. application text. The fact that such a step not only effectively removes the residual traces of contaminating proteins but also retains all the FSH biological activity is surprising in view of the article by P. Hallin and S.A. Khan (J. Liq. Chromat. 9(13), 2855-68, 1986) which shows loss of biological activity for bovine FSH and for human FSH
(standard of HMG) when they are subjected to reverse-phase HPLC. On the other hand, the same article shows a satisfactory recovery of biological activity, but only partial separation, when the human urinary preparation (i.e., containing both FSH
and LH) is subjected to ion-exchange HPLC.

_ ~~40~49 Following the HPLC step, FSH is recovered using conventional tech-niques. For storage and/or handling purposes, the product can be lyo-philized. Other suitable procedures to effect concentrating, stabiliz-ing or other processing of the product are contemplated.
Clearly, the availability of post-menopausal urine is greater than that of human pituitary glands. This relative availability lends dramatic importance to Applicant's discovery.
The FSH-specific monoclonal antibody for use in the process of this invention may be produced using known techniques.
In a typical example, hybridoma cell line 9/14 was screened for optimal affinity towards FSH at the University of Cambridge.
Monoclonal antibodies were produced in supernatant medium by cell culture techniques and purified by means of salt fractionation using 50$ (w/v) ammonium sulphate followed by ionic reverse-phase chromato-graphy and HPLC gel filtration and dialysis.
The monoclonal antibody produced by cell line 9/14 and purified as described above had the following specifications:
a) protein purity: not less than 90$
b) class of imanunoglobulin: IgG 1 c) affinity constant: 3.5 x 108 L.mole 1 d) specificity:
Antigen $ cross reaction HCG-beta subunit 1 ~~~oo~.o e) binding capacity to FSH in solution: about 1,000 I.U. FSH per mg hlcAb .
FSH-specific monoclonal antibodies are chemically bound to Sepharose 4B by divinylsulphone according to the method described by J. Porath in Methods in Enzymology 34, pages 13-30, 1974.
In a typical example, 1 litre of Sepharose 4B was washed on a porous glass filter first with 5 litres of freshly distilled water and then with 5 litres of 1 M sodium carbonate, pH 11. The washed Sepharose was suspended in 1 litre of 1 M sodium carbonate (pH 11) . 200 ml of divi-nylsulphone were added dropwise with continuous stirring. The reaction was completed in 70 minutes at room temperature and then stopped by means of the addition of 1 N HC1 (up to pH 7.0).
The activated resin was suspended in 1 litre of 0.25 M sodium bicar-bonate (pH 9.0) containing 2 grams of anti-FSH monoclonal antibody to obtain more than 90~ binding of the antibody to the activated resin.
The immunoresin obtained was stored at 4'C.
The following ~cample 1 illustrates the two purification steps of the method of this invention as applied to commercial Ht~, i.e, the active ingredient in Pergonal(R) Serono.
It is understood that while HI~G is the preferred starting material in the invention process, the latter is also applicable to less purified materials such as post-menopausal urine concentrates and the like.
Good results have been obtained using as starting material a urinary concentrate containing as low as 1 I.U. FSH per mg.
ether aspects and advantages of the invention will become apparent after consideration of the following examples, which are not intended to be limiting.

- to - l3~Ob49 EXAi~LE 1: Preparation of higly purified urinary FSH (hpuFSH) 1st Step: Immunopurification on anti FSH McAb-DVS-Sepharose F~ was used as starting material.
Imrrunoresin anti-FSFi Mcab-I~VS-Sepharose was equilibrated in 0.1 M
Tris-HQ ( 0.3 M NaCl buffer ~i=7.5 at 4°C.
the column was loaded with a quantity of IU FSH (RIA) corresponding to 80-90$ of its total FSH binding capacity.
'Ihe non-retained proteins were eluted with the equilibrating buffer until the OD280 of eluate was lower than 0.02.
'Ihe absorbed uFSH was eluted from the immunoresin with 1 M ar~nia solution at 4°C. Ammonia eluates corresponding to about 4 times the im~unoresin volume were pooled, the ~i was adjusted to 9.0 as soon as possible at 4°C by adding glacial acetic acid and the solution was ultrafiltered in an Amicori apparatus (membrane C.O. 10,000 .Ds) and concentrated to a small volume.
2nd Step: Reverse phase HPLC
the resultant solution, adjusted at pH=5.6, was loaded on a C18 reversed phase column (Pre Pak* Waters) which had previously been equilibrated with 0.05 M ammonium acetate pH=5.6 buffer at room temperature.
Flow rate was 100 ml/min and the eluatP was rrbnitored at 280 nm.
*
The HPLC purification was carried out employing a Prep 500 A apparatus (Waters) equipped with W detector and a preparative gradient generator Biologically active highly purified urinary FSH was eluted by a gra-dient of isopropanol up to 50$ of the mobile phase. Fractions were checked by analytical GPC and RIA.
The organic solvent was removed by distillation under vacuum at 40°C
*Trademark ~~ ~e1 and then the solution was frozen and lyophilized.
EXAMPLE 2: Characterization of the FSH
Zhe highly puri:°ied urinary FSH preparation of the present invention was subjected to several chemico-physical, biological and immunological tests in order to achieve its complete characterization. As indicated below, most of the tests were carried out in cortparison with a highly purified pituitary FSH preparation obtained according to the procedure described below.
Crude huUnan pituitary extract (HPG), a by-product resulting from extraction of the Iiurnan Growth Hormone, was used as starting material.
Zhe procedure consisted of the following steps:
1) Preliminary purification of crude HPG by extraction with 40%
ethanol containing 6% amcr~nium acetate pH 5.6 and precipitation of supernatant with 96% cold ethanol.
2) Flrther purification of HPG by ion exchange chromatography on DFAE
cellulose, using 0.15 M sodium acetate pH 7 as eluent, followed by precipitation with 96% cold ethanol.
3) Fl~rther purification of FSH fraction by gel filtration on Sephadex G-100, using 0.05 M ammonium bicarbonate as buffer.
4) Last step of FSH purification by ion exchange chromatography on SP
Sephadex C 50. Highly purified pituitary FSH was eluted with 0.1 M
phosphate buffer pFi 6.2 and lyophilized.
Zhe pituitary FSH in-vivo biological specific activity (Steelman-Pohley test: I.U. of 2nd IRP-HhG) was determined to be 4770 I.U. FSH/fig of lyophilized powder using the methodology described below under "Bio-v34~b~

logical Assay".
The characterization tests performed were as follows:
LH contamination This test was carried out by means of a specific radioimmunoassay for Lei using an LH standard calibrated against the 2nd IRP-HIrG and 1251-~ as the tracer, both contained in the IIi ter KIT (code 10204) currently marketed by the company Biodata (R). As antiserum, a sheep anti-HCG antiserum prepared by the Applicant was used having 100% cross-reactivity to Iii and less than 0.1% to FSH.
Zhe RIA procedure as per the manufacturer's instructions was followed to obtain as a result no detectable LH contamination in the highly purified urinary FSH preparation prepared in accordance with the Example 1.
The above results were confirmed using a more sensitive assay called DELFIA (dissociation - enhanced lanthanide fluoro immunoassay) marketed by LKB-Pharmacia.
CflC _ DT!''c Slab-gel electrophoresis in SDS was performed, under reducing conditions, on 13.5% polyacrylamide gel pEi - 8.8 according to the procedure described by Laemmli in Nature, 227, pages 680 - 685 (1970).
Staining was performed with Coomassie Brilliant Blue R-250 0.25% in a 25% methanol / 75% acetic acid solution.
Both the hpuFSH preparation according to the invention and the highly purified pituitary FSH preparation (hppFSH) obtained as described above were subjected to this test. Results are illustrated in Figure 1 where the bands of both the urinary and pituitary FSx preparations -13 - 1340~4~
(uFSH and pFSH, respectively) are shown together with the rrplecular weight markers (M.W.).
In both the uFSH and pFSH preparations the main large band typical of the glycoproteins is found at the same molecular weight of approxi-mately 20,000 Daltons, which is also in accordance with the literature data) Due to the known behaviour of the glycoproteins in SDS - PAGE, this value is a little overestimated.
Size exclusion chromatoqra by Analyses of both hpuFSH and hppFSH were performed on a TSK G 2000 SW
column by I1CB using 0.1 M phosphate buffer pH 6.8 + 0.2 M NaCl as the eluent. Flow was 0.7 ml/minute and readings were made at the wave-length of 230 manometers.
Results are illustrated in Figure 2 which shows single main peaks for both uFSH and pFSH with substantially the same retention times (13.37 and 13.55 minutes, respectively).
Isoelectrofocusing Isoelectrofocusing was carried out on 5$ thin-layer polyacrylamide gel (Anpholine LKB(R), pH range 3.5 to 9.5) fixed in 11.5$ (w/v) ZCA and 3.5~ (w/v) sulphosalicylic acid and stained with a Silver staining BIO-RAD(R) Klt.
Results for both hppFSH and hpuFSH are illustrated in Figure 3 which also shows the isoelectric point markers. As can be seen from the fig-ure, both urinary and pituitary FSHs show several bands but completely different patterns; in particular, the main bands of urinary FSH are at a pH range lower than 4.8 whereas pituitary FSH shows the main bands at a higher pH range.

J Sf This test demonstrates that urinary and pituitary FSHs are not iden-tical molecules and that the differences reside at least in their carbohydrate moieties, if not in the protein moieties themselves.
Biological assay The FSH in-vivo biological activity of hpuFSH was tested by the Steel-man Pohley method (E~docrinology 53, pages 604 - 616, 1953) using as the reference material an Ht~ House Standard calibrated against the 2nd International Reference Preparation of HMG for bioassay. 'Ibis assay is accepted by all major Pharmacopoeias and Health Authorities for the determination of the International Units (I. U.) of FSH biological activity.
The hpuFSH preparation obtained according to the E~cample above was determined to have a specific activity of 6200 I.U. of FSH per mg of lyophilized powder, i.e., the highest specific activity_ ever described for an FSH urinary preparation.
Determination of the Amino Acid sequence a) uFSH Subunit Separation The separation of the uFSH subunits is perfor~d using a Waters HPLC system equipped with a column Pquapore*FtP-300, 2U0 x 4.6 mn, 7 um, (Brownlee Labs).
The eluents are A = 0.1$ TFA (Trifluoroacetic acid, HPLC grade, Pierce), B = 0.055$ TFA in Acetonitrile. ~e flow rate is 1 ml/min at 35'C and the initial condition is 15$ B.
~e gradient raised 40$ B in 20 min.
The W detector is set at 229 nm.
Usually in analytical runs 20 r~l of a solution 0.5 mg~nl of hpuFSH
and 0.5$ TFA is injected. Preincubation in TFA solution is not necessary.
*Trademark -15 - 1344~4~
~e preparative separation is performed using the same column.
Good resolution is achieved by injecting 0.5 m3 of hp human a FSH
(batch n~' 032) dissolved in A buffer. Fractions are collected manually and dried down using a Speed Vacs concentrator. Subunits are dissolved in water, analized by HPLC and stored at -20'C.
The beta subunit is eluted after about 10.5 min as a broad peak, the alpha subunit elutes at 15 min as a sharp peak.
The recognition of each peak as beta and alpha subunit respectively is accomplished by a specific RIA.
Usually the recovery of the beta subunit is around 50$, the alpha subunit recovery on the contrary is more than 90~.
b) Reduction and Carboxymethylation of the alpha and beta Subunits.
Reduction of the subunits, separated as described in point a), is performed in 0.5 Tris, 0.1$ mTA, 6M Guanidine HC1 pH 8.5 for 2 h at 37'C using DTT (dithiothreitol, Serva) in 15 fold molar excess over cystein content.
Sodium iodoacetate (2.1 molar over DTT) is then added to the reaction mixture and left lying for 30 min in the dark.
To stop the reaction 1~ mercaptoethanol and TFA is added.
The carboxymethylated subunits are purified by HPLC.
The beta carboxymethylated subunit is poorly soluble in water so that the final yeld is quite low.
c) Reduction, pyridylethylation and trypsin digestion of the beta subunit Reduction of the beta subunit, separated as described in point a) was performed at room temperature for 2 hrs in the following way:
0.1 mg of beta subunit .
0.5 ml of O.SM Tris, 0.1~ EFTA, 6M guanidine HC1 I~Ei 8.5 2.7 mg Dithiothreitol *Trademark 13~U~f.~~

The Pyridylethylation was performed adding 0.02 ml of 4 vinyl-pyridine to the previous solution.
the reaction takes 2 hrs at room temperature. Finally, the reac-tion mixture was loaded onto a C4 Cartridge (Baker) equilibrated with 0.1% TFA.
The cartridge was washed with 0.1% TFA and the beta subunit pyridylethylated was eluted with 40% Acetonitrile, 0.1% TFA. The eluted fraction was dried down and purified by I~LC as previously reported for the beta subunit.
The pyridylethylated beta subunit previously purified by F~LC was dissolved in 1% t~i4i-iC03' pH 8) The trypsin was added to the solution and the reaction was carried out for 1.5 hrs at 37'C.
The tryptic fractions were purified by FB?LC using the same pro-cedure previously described, except for the gradient from 0% to 55% in 30' and the W detector, set at 214 nm.
The tryptic fractions were sequenced in the same way reported for the sequencing of the subunits (cf. point e)).
d) Sequencing of the alpha subunit Several sequencing runs are performed using alpha subunit, carboxy-methylated alpha subunit, or integral highly purified human uFSH
usually loading 5 nmoles or less into the protein sequencer (470 A, Applied Biosystem) and using the standard 03RPTH program delivered by Applied Biosystem or a special program where cycles which cleave a Pro or a Gly are substituted by the special cycle 03CPRU.
Ttie first 45 residues starting from NH2 terminal of the molecule were identified and the results confirm the amino acid sequence known from the literature (J. Biol. Chem. 250, 6735 (1975).

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Zhe Asn at position 52 and at position 78 referring to the known sequence starting with Ala are the amino acids where glycosylation occurs.
At the NH2 terminal is always present an heterogeneity and is always the same in all samples sequenced. Zhe complete molecule (i.e, starting with Ala) is present in 65$ of the chains, the molecule missing the first two amino acids (i.e. starting with Asp) is present in 5$, the molecule missing the first three amino acids (i.e. starting with Val) is present in 30$.

65~ of chains Ala Pro Asp Val Gln ....

5$ of chains Asp Val Gln ....
30$ of chains Val Gln ....
Heterogeneity of alpha subunit.
e) Sequencing of the beta subunit Several sequencing runs were performed using beta subunit, carboxy-methylated beta subunits, integral highly purified human u-FSH and tryptic peptides from pyridylethylated beta subunit.
Zhe samples were loaded into the protein sequencer (470 A, Applied Biosystem) using the standard 03RPTH program delivered by Applied Biosystem.
The results show that the beta-subunit is 111 amino acids long and has the following amino acid sequence:
Asn Ser Cys Glu Leu Thr Asn Ile Thr Ile Ala Ile Glu Lys Glu Glu Cps Arg Phe Cps Ile Ser Ile Rsn Zhr Zhr Trp Gds Ala Gly Tyr Cys Tyr Zhr Arg Asp Leu Val Tyr Lys Asp Pro Ala Arg Pro Lys Ile Gln Lys Zh r Cys Thr Phe Lys Glu Leu Val Tyr Glu Zhr Val Arg Val Pro Gly Cps Ala His 134~~49 ~0 His Ala Asp Ser Leu err 2fir err Pro Val Ala Thr Gln Cps His Cys Gly Lys Cars Asp Ser Asp Ser 2hr Asp Cars Thr Val Arg Gly Leu Gly Pro Ser Tyr Cps Ser Phe Gly Glu Met Lys Glu The Asn at position 7 and 24 referring to the above sequence starting with Asn at position 1 are the amino acids where glycosilation occurs.
At the NH2 terminal of beta subunit is always present an heterogeneity and is always the same in all sarr~les sequenced. The coaplete molecule (i.e. starting with Asn) is present in 35$ of the chains, the molecule missing the first amino acids (i.e. starting with Ser) is present in 15$, the molecule missing the first two amino acids (i.e. starting with Cys) is present in 50~.

35$ of chains Ser Gds Gly Leu ....
Asn 15$ of chains Ser Cps Glu Leu ....

50$ of chains Cars Gly Leu ....

Heterogeneity of beta subunit.
EXAMPLE 3: Pharmaceutical preparations The production of pharmaceutical dosage form preparations containing hpuFSH obtained in accordance with this invention is not particularly difficult) Since the substance maintains its biological activity after lyophilization, this is the preferred form for injectable preparations.
The lyophilized hpuFSH-containing preparation is reconstituted using physiological saline and/or other suitable diluents to yield an in-jectable solution.
Some excipients may be suitably used in the composition as a part thereof, such as, for example, mannitol, lactose, glycine, glucose, saocharose and their mixtures. Other conventional carriers, fillers ~.~4064~

and the like can be used. Mixtures are operable.
In the experiments carried out according to the present invention, lactose has been used as the excipient for the injectable preparations.
In preparing injectable formulations, pH is optionally adjusted via the addition of conventional acidic or basic substances. Acidic substances include acetic acid and the like. Basic substances include sodium hydroxide and the like. Mixtures can be employed.
The use of one or more stabilizers, e.g. albumin and the like, is contemplated.
A typical example of pharmaceutical production for the manufacturing of a batch of 20,000 ampoules each containing 75 I.U. FSH is as follows .
The calculated (in units of biological activity) amount of the lyophi-lized FSH bulk powder is dissolved in 700 ml of cold apyrogenic water for injection. If necessary, pH is readjusted to a value between 6.2 and 6.8 by using either acetic acid or sodium hydroxide, as the case may be. The solution is then sterile filtered through a 0.2 micron pores filter.
200 grams of lactose are dissolved in 2 litres of apyrogenic water for injection, sterile filtered as above and added to the FSH solution.
Apyrogenic water for injection is added to reach a final volume of 15 litres, the solution is dispensed into ampoules (0.75 ml each) and lyophilized in a sterile lyophilizator.
Ampoules are obtained which contain each 75 I.U. FSH and 10 mg lactose.
In a preferred embodiment the ampoules may contain 150 I.U. FSH.
According to a further example of pharmaceutical preparation, ampoules have been prepared which also contain 1 mg of human albumin as stabilizer in addition to the excipient lactose.
Although this invention has been illustrated with specific examples, it is understood that variations may be made without departing from the spirit and scope of the invention.

Claims (21)

1) A protein comprising an alpha- and a beta-subunit, wherein the alpha-subunit is a gonadotropin alpha-subunit and the beta-subunit has the following amino acid sequence:
Asn Ser Cys Glu Leu Thr Asn Ile Thr Ile Ala Ile Glu Lys Glu Glu Cys Arg Phe Cys Ile Ser Ile Asn Thr Thr Trp Cys Ala Gly Tyr Cys Tyr Thr Arg Asp Leu Val Tyr Lys Asp Pro Ala Arg Pro Lys Ile Gln Lys Thr Cys Thr Phe Lys Glu Leu Val Tyr Glu Thr Val Arg Val Pro Gly Cys Ala His His Ala Asp Ser Leu Tyr Thr Tyr Pro Val Ala Thr Gln Cys His Cys Gly Lys Cys Asp Ser Asp Ser Thr Asp Cys Thr Val Arg Gly Leu Gly Pro Ser Tyr Cys Ser Phe Gly Glu Met Lys Glu the protein having a specific follicle stimulating hormone (FSH) activity of not less than 6,200 I.U. of FSH per mg of lyophilized powder and being substantially free from detectable traces of luteinizing hormone (LH) and other urinary proteins.

2) A protein according to claim 1 wherein the beta-subunit has 110 amino acids and corresponds to the amino acid sequence as defined in claim 1 but lacks the starting Asn (position 1).

3) A protein according to claim 1 wherein the beta-subunit has 109 amino acids and corresponds to the amino acid sequence as defined in claim 1 but lacks the starting Asn and the Ser at position 2.

4) A protein according to claim 1 wherein the gonadotropin alpha-subunit has the following amino acid sequence:

Ala Pro Asp Val Gln Asp Cys Pro Glu Cys Thr Leu Gln Glu Asn Pro Phe Phe Ser Gln Pro Gly Ala Pro Ile Leu Gln Cys Met Gly Cys Cys Phe Ser Arg Ala Tyr Pro Thr Pro Leu Arg Ser Lys Lys Thr Met Leu Val Gln Lys Asn Val Thr Ser Glu Ser Thr Cys Cys Val Ala Lys Ser Tyr Asn Arg Val Thr Val Met Gly Gly Phe Lys Val Glu Asn His Thr Ala Cys His Cys Ser Thr Cys Tyr Tyr His Lys Ser.

5) A protein according to claim 4 wherein the alpha-subunit has 90 amino acids corresponding to the amino acid sequence as defined in claim 4 but lacks the starting Ala and the Pro at position 2.

6) A protein according to claim 4 wherein the alpha-subunit has 89 amino acids and corresponds to the amino acid sequence as defined in claim 4 but lacks the starting Ala, the Pro at position 2 and the Asp at position 3.

7) A protein according to claim 1 in glycosylated form.

8) A protein according to claim 7 wherein the Asn at position 7 and 24 of the beta-subunit(s) and the Asn at position 52 and 78 of the alpha-subunit(s) are glycosylated.

9) A protein according to claim 1, 2, 3, 4, 5, 6, 7 or 8 which is extracted from human menopausal urine.

10) A process for preparing a protein according to claim 1 characterized in that it includes the steps of subjecting a post-menopausal urinary concentrate to immunopurification using FSH-specific immobilized monoclonal antibodies, eluting to recover the FSH and removing any residual traces of contaminants by reverse phase HPLC, wherein the elution of FSH is carried out using as eluent an aqueous solution having a pH higher than about 10 and a molarity higher than about 0.5.

11) The process of claim 10 characterized in that the post-menopausal urinary concentrate is human menopausal gonadotropin.

12) The process of claim 10 wherein the eluent has a pH within the range of 11.3 to 11.7 and a molarity of about 1.

13) The process of claim 12 wherein the eluent is 1 M ammonia.

14) A pharmaceutical preparation containing a therapeutically effective amount of a protein according to claim 1 and a pharmaceutically acceptable excipient.

15) A pharmaceutical preparation according to claim 14 wherein the excipient is lactose.

16) An injectable lyophilized pharmaceutical preparation according to claim 14 or 15.

17) A pharmaceutical preparation according to claim 14 or 15 adapted for subcutaneous administration.

18) A pharmaceutical preparation as claimed in claim 14 which contains about 75 I.U. of FSH per ampoule.

19) A pharmaceutical preparation as claimed in claim 14 which contains about 150 I.U. of FSH per ampoule.

20) A pharmaceutical preparation as claimed in claim 14 or 15 comprising human albumin as stabilizer.

21) The use of a protein according to claim 1 for the treatment of infertility.