DE3141419A1 - Pro-peptides of proalbumin, process for their preparation and their use - Google Patents

Abstract

Pro-peptides of proalbumin in the form of the hexapeptide of the formula Arg-Gly-Val-Phe-Arg-Arg or the fragments thereof, a process for the synthesis of these pro-peptides and their use for the measurement of in vivo serum albumin synthesis and/or of the activity of antagonists are described.

Description

description

The invention relates to pro-peptides of proalbumin, a method for their manufacture and use.

It is already known that proalbumin is the intracellular precursor of serum albumin and differs from serum albumin in that it is on N-terminal end carries an oligopeptide. In a sequence analysis of rat proalbumin it has been shown that the oligopeptide bound to the polypeptide chain of serum albumin the hexapeptide is Arg-Gly-Val-Phe-Arg-Arg (The Journal of Biological Chemistry, Vol. 250, No. 9 (1975) 3409 to 3413 and Vol. 255, No. 7 (1980) 3156 to 3163). It is believed that the corresponding pro-peptide of human serum albumin in the same Manner (Nature 274 (1978), 908 to 909). It could be shown, that this oligopeptide is split off in the Golgi apparatus with the help of an enzyme, which has the properties of cathepsin B (Biochem. Biophys. Res.

Commun. 72 (1976) 310 to 318 and 319 to 326 and Biochem.

J. 172 (1978) 301-309).

So far, however, the free hexapeptide has been given its above Amino acid sequence was determined in the form bound to serum albumin, not described and there was also no available procedure for its synthesis to the person skilled in the art available because three of the six amino acids in the hexapeptide are arginine. These The very basic amino acid poses considerable synthetic problems that have not yet occurred could not be resolved.

The object of the present invention is therefore to provide pure, to create synthetic pro-peptides of proalbumin that are in their amino acid sequence correspond to the above-mentioned hexapeptide or fragments thereof and a method indicate with which their production appears possible.

This object is now achieved by the pro-peptides according to the main claim and the method for their preparation.

The invention therefore relates to pro-peptides of proalbumin which are characterized by the hexapeptide of the formula I Arg-Gly-Val-Phe-Arg-Arg (1) its fragments and the salts of these peptides, in particular their acetates.

The above hexapeptide of the general formula I has in the form of Triacetats the following physical characteristics: 57436 = 59O (c = 3.5 in water) Thin-layer chromatogram: a) Rf = 0.48 (ethyl acetate / pyridine / acetic acid / water 15/20/6/11, Vol / vol) b) Rf = 0.25 (ethanol / pyridine / acetic acid / water 30/20/6/4, vol / vol).

A preferred fragment of the hexapeptide of the general formula above I is the pentapeptide of the following formula II Gly-Val-Phe-Arg-Arg (11) which has the following physical characteristics in the form of the diacetate: / X72036 = 310 (c = 4.33 in water) Thin-layer chromatogram: Rf = 0.32 (n-butanol / acetic acid / pyridine / water, 4/1/1/2, vol / vol), Rf = 0.24 (ethanol / pyridine / acetic acid / water, 30/20/6/4, vol / vol).

Another preferred fragment of the hexapeptide mentioned above is the tetrapeptide of the following formula IV Arg-Gly-Val-Phe (IV), which is in the form of the acetate has the following physical characteristics: --20 = 480 (c = 1 in Water) LX! 436 thin layer chromatogram: Rf = 0.62 (ethanol / pyridine / acetic acid / water 30/20/6/4, vol / vol).

Further preferred fragments of the hexapeptide of the formula I are Pentapeptide of the following formula III Arg-Gly-Val-Phe-Arg (III) and the tetrapeptides of the following formulas V and VI Gly-Val-Phe-Arg (V) Val-Phe-Arg-Arg (VI) It has surprisingly been shown that the pro-peptides according to the invention, d. H. the hexapeptide of the general formula I and its fragments of the general Formulas II to VI very simply according to the synthesis method known per se via the Mixed anhydrides can be produced if one is doing this from a specific starting material and the mixed problems caused by the amino acid arginine Salt formation is solved by using a basic agent, namely a strong lye adds to expose all of the basic groups in the amino acids, and they then with an acid again into a uniform, physiologically compatible salt convicted.

It was also possible to use these peptides on the polymeric carrier of (Ng-tosyl) arginine and polymer-bound benzyl ester or methyl ester using trifluoromethanesulfonic acid as a protective group and peptide-releasing agent Reagent according to methods known per se.

The invention therefore also provides a method for production the pro-peptides of the type defined above, which consists in making the peptide chain from the C-terminal end by stepwise N-terminal peptide chain extension builds up according to the known method of mixed anhydrides in solution, or the sequence is synthesized on the polymeric carrier by methods known per se, starting out of N-tert-butyloxycarbonyl- (N-nitro) -arginyl- (Ng-nitro) -arginine-4-nitrobenzyl ester, N-tert. -Butyloxycarbonyl- (Ng-tosyl) -benzyl ester, polymer-bound benzyl ester or polymer-bound methyl ester, the protective groups according to methods known per se splits off and, by adding a basic agent, all basic groups of the Pro-peptides are released and then with an acid a uniform, physiologically forms acceptable salt.

Dilute sodium hydroxide solution is preferably used as the basic agent, Potash lye or strongly basic hydroxyl ion exchanger and acetic acid as acid, since in this way the physiologically acceptable acetates are formed directly.

It has surprisingly been shown that the inventive Hexapeptide of the general formula I in raw ren concentrations has a strong inhibition of albumin synthesis, while the overall protein synthesis is less potent being affected. It is believed that the inhibition of albumin synthesis by this hexapeptide both in the cell-free system and in isolated hepatocytes the synthesis of preproalbumin is influenced via a feedback mechanism which its own pro-peptide acts as an inhibitor. It seems that the hexapeptide of general formula I for the transmission of information from the albumin present in the plasma is responsible for its intracellular synthesis site is. This makes it possible to synthesize albumin and possibly others Affecting plasma proteins.

On the other hand, it has surprisingly been found that the inventive Hexapeptide of the formula I occurs in the serum itself and is detectable there, as a result of which the quantitative detection of this hexapeptide in the serum becomes possible. That way it becomes possible, the extent of the serum albumin synthesis or a possible lack of synthesis diagnose directly. This is particularly important for certain forms cirrhosis of the liver, in which the new synthesis of serum albumin is inhibited. It is it is possible that in these clinical pictures the inhibition is too high is due to the hexapeptide of the general formula I, so that it has a Antagonists of this hexapeptide are able to specifically stimulate serum albumin synthesis.

The invention therefore also relates to the use of the invention Pro-peptides for measuring or regulating the in vivo serum albumin synthesis and / or the effectiveness of antagonists of these pro-peptides.

The following examples serve to further illustrate the invention.

Example 1 Production of the Propeptides According to the Invention Starting with from 4-nitrobenzyl bromide is formed according to the method described in Chem. Ber. 97 (1964) 2490 Procedure the ester of N «-tert.-Butyloxycarbonxyl- (Ngnitro) arginine. from the crystalline product is cleaved the N-terminal protective group at 0 ° C. with trifluoroacetic acid and sets the material obtained by the mixed anhydride method Use of isobutyloxycarbonyl chloride / N-methylmorpholine (J. Amer.

Chem. Soc. 89 (1967) 5012 to 5017) with N «-tert.Butyloxycarbonyl- (Ng-nitro) arginine around.

Then the amino acid sequence is gradually extended using of excess mixed anhydrides of Nα-3,5-dimethoxy-α, α-dimethylbenzyloxycarbonyl-amino acid (Ddz-amino acids) using the in Int. J. Peptide Protein Res. 13 (1979) 287 to 295 to the hexapeptide Arg-Gly-Val-Phe-Arg-Arg.

Furthermore, one prepares starting from the mixed anhydride of Ddz-Gly-Val-Phe with Arg (NO2) Arg (NO2) OBzl (NO2) the pentapeptide. After the cleavage of the N-terminal Protection group of the pentapeptide and reaction with the mixed anhydride of Ddz-Arg (N02) the hexapeptide is obtained in identical quality.

To prepare the N-terminal tetrapeptide one couples in the above described way the mixed anhydride of Ddz-Arg (Tos) to Gly-Val-Phe-OBu t.

By catalytic hydrogenation (24 hours, 20 ° C) in 80% acetic acid with palladium (10%) on activated carbon or

by reaction in pyridinium polyhydrogen fluoride for 60 minutes in the case of OOC, the protective groups of the fully protected pentapeptides and hexapeptides are cleaved away. In the latter reaction, the material is precipitated with dry material at -700C Ether out, separates it off, washes it with dry ether and leads it over an in the acetate form present ion exchanger (Dowex 1x2).

The tetrapeptide is also made by treating with pyridinium polyhrogen fluoride freed from the protective group. All crude arginine peptide products are in the acetate form freeze-dried and purified by chromatography in water under sterile conditions (Sephadex G15 (3 x 230 cm), Biogel P6 (1 x 200 cm) and LiChroprep RP8 (Merck)), monitoring the elution via the UV spectrum at 254 nm.

The purification is carried out by thin layer chromatography using the following solvent systems monitored: A: (ethyl acetate / pyridine / acetic acid / water 15/20/6/11, vol / vol) B: (n-butanol / acetic acid / pyridine / water 4/1/1/2, vol vol) C: (Ethanol / pyridine / acetic acid / water 30/20/6/4, vol / vol) D: (n-butanol / acetic acid / water 4/1/1, vol / vol) E: (chloroform / methanol / acetic acid 8/1/1, vol / vol).

The optical rotation values are measured using a polarimeter (Perkin-Elmer Polarimeter Model 241).

The following products and intermediates were isolated.

a) Boc-Arg (NO2) OBzl (NO2) yield: 92% L «£ 723605 = -12 ° (c = 1% in dimethylformamide) Thin-layer chromatogram: Rf = 0.83 (solvent system D) Elemental analysis: C% H% N% found: 42.74 5.97 22.56 calculated: 43.96 5.68 23.50 b) Ddz-Phe-Arg (NO2) -Arg (NO2) OBzl (NO2) Yield: 83% Thin-layer chromatogram: Rf = 0.64 (solvent system E) c) Ddz-Val-Phe-Arg (NO2) Arg (NO2) OBzl (NO2) Yield: 67% thin layer chromatogram: Rf = 0.26 (solvent system E) d) Ddz-Gly-Val-Phe-Arg (NO2) OBzl (NO2) yield: 65% (60% yield with fragment condensation) thin layer chromatogram: Rf = 0.30 (solvent system E) e) Ddz-Arg (NO2) Gly-Val-Phe-Arg (NO2) Arg (NO2) OBzl (NO2) Yield: 770 mg = 80% (700 mg = 94% in the fragment condensation) [α] 20 = 54O (c = 1% in acetic acid) 436 thin-layer chromatogram: Rf = 0.40 (solvent system E) Melting point: 128 to 1300C.

f) Arg-G £ y-Val-Phe.AcOH (acetate of the tetrapeptide of the general formula IV) [α] 20 = -48 ° (c = 1% in water) 436 thin layer chromatogram: Rf = 0.62 (Solvent system C) Amino acid analysis: Gly = 1.14 (1), Val = 1.01 (1), Phe = 1.04 (1), Arg = 1.17 (1).

Yield: 380 mg of the crude product, 90% yield based on that fully protected tetrapeptide.

Purified product: 70 mg.

g) Gly-Val-Phe-Arg-Arg.2AcOH (diacetate of the compound of formula II) [α] 20 = -31 ° (c = 4.33 in water) 436 thin layer chromatogram: Rf = 0.32 (Solvent system B) Rf = 0.24 (solvent system C) amino acid analysis: Gly = 1.14 (1), Val = 1.12 (1), Phe = 1.00 (1), Arg = 2.17 (2) Yield: 350 mg of the crude are obtained Product, which corresponds to a yield of 85% based on the fully protected pentapeptide, is equivalent to.

Purified product: 33 mg.

h) Arg-Gly-Val-Phe-Arg-Arg.3AcOH (triacetate of the hexapeptide of the formula I) [α] 20 = -590 (c = 3.5 in water) 436 thin layer chromatogram: Rf = 0.48 (Solvent system A) Rf = 0.25 (solvent system C) amino acid analysis: Gly = 1.21 (1), Val = 0.98 (1), Phe = 1.02 (1), Arg = 3.00 (3) Yield: One obtains 610 mg of the crude product, representing a 67% yield based on the complete protected hexapeptide1 corresponds to purified product: 160 mg.

The products of Example 1 f), g) and h), d. H. the tetrapeptide of formula IV, the pentapeptide of formula II and the hexapeptide of formula I were examined by high performance liquid chromatography using a column with a length of 120 mm and an inner diameter of 4.6 mm (phase: Shandon, Carrier: ODS) Mobile phase and gradient: A = 0.1m KH2PO4 (H3PO4, pH = 2.1; B = CH3CNiO up to 60% Bm 2% per min.

The high performance liquid chromatographic separation of a mixture of these three peptides using a flow rate of 1 ml / min the following retention times: tetrapeptide of formula IV 19.26 min, pentapeptide of formula II 10.25 min. hexapeptide of formula I 9.74 min.

Although in the claimed procedure the synthesis of the C-terminal Peptide Arg (NO2) Arg (NO2) OBzl (NO2) facilitated by the production of the nitrobenzyl ester this ester residue generally leads during peptide elongation to problems. This is due to the fact that the arginine side chain is only partially protected apparently an autocatalytic effect on the transesterification of the during the synthesis Exercises C-terminal nitrobenzyl ester in methanol. So they were chromatographically cleaned ten (Sephadex LH20 / methanol) intermediates always from Accompanied by peptide methyl esters. With a repeated production of the hexapeptide this effect can be avoided by the nitrobenzyl ester in the Saponified stage of the C-terminal tetrapeptide.

The splitting off of the guanidino protective function from the arginine peptides by catalytic hydrogenolysis of the nitro groups leads to a cleanliness of impurities, which are also present, but in a different form, if the protective groups with Pyridinium polyhydrogen fluoride are split off.

The essential and surprising effect of the claimed method is, however, that those occurring in the salt formation of the guanidino groups Problems related to purity and by-product formation that too cannot be avoided by using an anion exchanger in acetate form can be solved. So the complete conversion of all salts gives the Guanidino groups with dilute sodium hydroxide solution, followed by acidification with acetic acid, homogeneous and physiologically acceptable salts of arginine peptides, which, finally, by chromatographic methods of desalination of inorganic salts need to be freed.

Example 2 Biological investigation of the pro-peptides according to the invention In this biological study, the hexapeptide of formula I, the pentapeptide of the formula II and the tetrapeptide of the formula IV are used. In doing so, the hexapeptide according to the method of Goodfriend et al.

(Science 144 (1964) 1344-1346) coupled to rabbit serum albumin. For this were about 10 mg of rabbit albumin and 10 mg of the hexapeptide dissolved in 0.5 ml of water. Separately, 100 mg of carbodiimide was dissolved in 0.25 ml of water solved. The two solutions were mixed and the reaction slowed down occasionally Shaking allowed to proceed at room temperature for 15 minutes. The pH of the The resulting reaction mixture was about 7. The reaction was carried out through 48 hours Dialysis against water ended. The indirect proof of the successful coupling was performed by measuring the free hexapeptide in the first dialysate. After this No hexapeptide could concentrate the dialysate by thin-layer chromatography can be detected, suggesting that more than 80% of the peptide is attached the albumin had been bound.

Two rabbits were immunized, including about 1 mg of antigen in the whole Freund's adjuvant suspended intradermally at weekly intervals became.

After the fifth week, blood was drawn and then used the animals were re-immunized with about 100 μg of the antigen every four weeks.

The enzyme-linked immunosorbent test method (ELISA -Enzyme-Linked-Immuno-Sorbent-Assay) with alkaline phosphatase bound to staphylococcus protein A and 4-nitrophenyl phosphate as the enzyme-substrate system was carried out in the manner described in J. Clin. Microbiol. 8 (1978) 473-479. The staphylococcus protein A was isolated and according to the method of Engvall and Perlmann (J. Immunol. 109 (1972) 129 to 135) coupled with alkaline phosphatase.

The polystyrene tubes were filled with 0.5 ml of a 0.2 % glutaraldehyde solution in 0.1m sodium phosphate buffer with a pH of 5 pretreated and then with 1 μl of the antigen dissolved in PBS with incubated at a pH of 6.8 for 3 hours at 370C. The free aldehyde groups were treated with 0.1m ethanolamine or bovine serum albumin (1 μg / ml) for 45 minutes saturated. The tubes were then given a 0.5 ml of the antiserum (which is diluted with PBS + 0.05% Tween 20 and 0.02% sodium azide was incubated.

After the addition of the alkaline phosphatase (70 mg / ml) coupled Staphylococcus protein A was made to react by adding 4-nitrophenyl phosphate (1 mg / ml) in 0.1m carbonate buffer with pH 9.6 by adding 1 mmol of MgCl2 set in motion. After 1 hour the reaction was stopped by adding 0.1 ml of 2N NaOH interrupted, after which the tubes were evaluated photometrically at 405 nm.

A two-dimensional immunodiffusion was carried out according to the method of Ouchterlony (Progr. Allergy 5 (1958) 1 to 78) in 1% agarose.

In this two-dimensional immunodiffusion, antibodies against the material used for immunization in the serum of both animals for one week after the last injection. That bound to rabbit albumin Hexapeptide gives a single line of precipitation with the antiserum. In contrast the antiserum does not form a precipitate with rat albumin in the absence of the hexapeptide, Rabbit albumin, rabbit serum and rat albumin when treated with carbodiimide have been. There is also no precipitation with normal rabbit serum and the coupled hexapeptide. Even with the uncoupled peptide there is none Precipitation. This suggests that the hexapeptide is only an antigenic determinant possesses, as a result of the inability of the hexapeptide-antibody complex, complements to bind is confirmed.

The least amount of the coupled hexapeptide that will interact with the Ouchterlony test can be demonstrated is 20 ßg.

When determining the free hexapeptide in the liver or plasma a test with a higher sensitivity is required. As a result, a indirect ELISA test method developed. This was either on rabbit albumin Coupled or uncoupled hexapeptide with glutaraldehyde on polystyrene tubes bound and then treated with antiserum. The alkaline phosphatase was attached to staphylococcus protein A coupled, which specifically and firmly with the Fc pieces of the immunoglobulins binds. When using 4-nitrophenyl phosphate disodium salt as a substrate the antibodies effective against the hexapeptide can be measured photometrically.

This test system has already been used with success on other antigens and this method of determination also enables the measurement of those antigen-antibody reactions, which are not accompanied by a precipitate.

In this case, too, the antibodies of the carbodiimide could Albumin-coupled hexapeptide can be detected in the sera of both animals, with however, a different antibody titer resulted in the two animals. While the rabbit antiserum # 1 has a maximum binding capacity for the heptapeptide at a dilution of 1: 6400 with an absorbance at 405 nm of 1.04, Rabbit # 2 antiserum shows maximum binding capacity upon dilution 1: 200 and an absorbance at 405 nm of 0.93. The antiserum is also used on Carbodiimide treated albumin and bound to native albumin, but essentially lesser extent with a maximum absorbance of 0.4 or 0.2, with a dilution the extinction is 1: 51200 both proteins at 405 nm 0.09 compared to 0.69 for the albumin coupled hexapeptide. This can be done by the simultaneous presence of antibodies for native rabbit albumin and rabbit albumin, which has been structurally changed by the action of the carbodiimide, be explained. A non-specific bond as a result of reactive carbodiimide groups could be another explanation. In all cases, the non-specific impaired Binding of the antibodies to structurally changed material under the action of the carbodiimide Rabbit albumin the measurements of the hexapeptide in the serum or in the liver homogenates not from rats and humans.

In contrast to the Ouchterlony test, the ELISA method the antibodies not only with the hexapeptide coupled to the albumin, but also with the uncoupled hexapeptide at a serum dilution of 1: 100 the absorbance at 405 nm for rabbit serum No. 1 is 0.26. The dilution of the antiserum leads to an exponential decrease in the absorbance at 405 nm, where a dilution of 1: 12800 results in the zero value. The negative control attempts with normal rabbit antiserum show a very low absorbance at 405 nm, which is never greater than 0.04. The pentapeptide of formula II and the tetrapeptide of formula IV are also bound to the antiserum, albeit to a lesser extent Extinction, resulting in a maximum absorbance at 405 nm of 0.04 and 0.09, respectively. The weak reaction with the tetrapeptide or the pentapeptide suggests a highly specific one Close the antibody reaction.

It is interesting that the tetrapeptide according to the invention of the formula IV shows a higher absorbance at 405 nm than the pentapeptide of formula II and that Bradykinin (Arg-Pro-Pro-Gly-Phe-Ser-Pro-Phe-Arg) also marginally with the Antiserum reacted. This could indicate that the N-terminal arginine is an essential Is part of the antigenic determinant.

These results of the biological examination indicate that both rabbits specific antibodies against the pro-peptide of the invention Forming trial albumin.

If you coat test tubes with these antibodies, you can Develop an ELISA detection method that measures the hexapeptide in plasma or in liver homogenates. Weighing through the liver of a rat of 200 g about 6.3 mg of albumin are synthesized per hour, the hexapeptide is split off from the trial albumin in equimolar amounts. From the molecular weight of the hexapeptide (880) and that of the rat albumin (64616) can be calculated that the rat liver produces 97 nmoles or 86 μg of the hexapeptide per hour. Included the plasma volume of a rat weighing 200 g is approximately 8 ml and the liver of this rat is 7 g.

Assuming that the hexapeptide is completely within the Liver remains or is completely released into the plasma, so one can Calculate the maximum hexapeptic concentration of 12 ßg / g liver or 11 ßg / ml of the plasma.

Since 1 ng / ml of the hexapeptide with the described ELISA determination method can be detected, this method enables the measurement of the hexapeptide itself when the distribution space is significantly larger than the plasma or liver volume. Furthermore, by using an immunofluorescent molecule or antibodies labeled with peroxidase determine the intracellular fate of the hexapeptide can be followed microscopically.

In each case results from the claimed pro-peptides of Proalbumins a considerable enrichment of the technology.

Claims (10)

Pro-peptides of proalbumin, process for their preparation and their Use of claims 1. Pro-peptides of proalbumin, g e k e n n z e i c h -net d u r c h the hexapeptide of the formula 1 Arg-Gly-Val-Phe-Arg-Arg, (I) which has the following physical characteristics in the form of the triacetate: [α] 20 = -59 ° (c = 3.5 in water) 436 thin layer chromatogram: a) Rf = 0.48 (ethyl acetate / pyridine / acetic acid / water 15/20/6/11, Vol / Vol) b) Rf = 0.25 (ethanol / pyridine / acetic acid / water, 30/20/6/4, vol / vol) its fragments and the salts of these peptides, in particular the acetates. 2. Pro-peptide according to claim 1, g e k e n n z e i c h -n e t d u r c h the pentapeptide of the formula II Gly-Val-Phe-Arg-Arg (11) and its salts, in particular its acetate. 3. Pro-peptide according to claim 1, g e k e n n z e i c h -n e t d u r c h the pentapeptide of the formula III Arg-Gly-Val-Phe-Arg (III) and its salts, in particular its acetate. 4. Pro-peptide according to claim 1, g e k e n n z e i c h -n e t d u r c h the tetrapeptide of the formula IV Arg-Gly-Val-Phe (IV) and its salts, in particular its acetate. 5. Pro-peptide according to claim 1, g e k e n n z e i c h -n e t d u r c h the tetrapeptide of the formula V Gly-Val-Phe-Arg (V) and its salts, in particular its acetate. 6. Pro-peptide according to claim 1, g e k e n n z e i c h -n e t d u r c h the tetrapeptide of the formula VI Val-Phe-Arg-Arg (VI) and its Salts, especially its acetate. 7. Process for the production of the pro-peptides according to claims 1 to 6, d u r c h g e k e n n -z e i c h n e t that the peptide chain from C-terminal end by stepwise N-terminal peptide chain extension the known method of mixed anhydrides in solution, or after methods known per se, the sequence is synthesized on the polymeric carrier, starting out of N-tert-butyloxycarbonyl- (N-nitro) -arginyl- (N-nitro) -arginine-4-nitrobenzyl ester, N-tert-butyloxycarbonyl- (Ng-tosyl) -arginyl- (Ng-tosylbenzyl ester, polymer-bound Benzyl ester or polymer-bonded methyl ester, the protective groups known per se Methods split off and all basic ones by adding a basic agent Groups of the pro-peptides are released and then with an acid a uniform, physiologically forms acceptable salt. 8. The method according to claim 7, d a d u r c h g e k e n n z e i c h n e t that one can use diluted caustic soda, caustic potash or strong as a basic agent basic hydroxyl ion exchanger and acetic acid as acid. 9. Use of the pro-peptides according to claims 1 to 6 for measurement the in vivo serum albumin synthesis and / or the effectiveness of antagonists thereof Pro-peptides. 10. Medicines for the regulation of in vivo serum albumin synthesis, d a d u r c h e k e k e n n -z e i c h n e t that there is a pro-peptide according to one of the Contains claims 1 to 6 as an active ingredient.