Placenta-derived anticoagulating substance

Claim 1

A human placenta-derived anticoagulating substance having the following properties: (1) molecular weight (SDS-polyacrylamide gel electrophoresis, reduced and non-reduced states): 73,000±2,000; (2) isoelectric point (isoelectric column electrophoresis using an ampholyte): 6.2-6.6; (3) stability: (a) inactivated by a heat treatment at 50° C. for 30 minutes, (b) stable in a pH range of 5.5-8.5 (37° C.), (c) stable in plasma at 37° C. for 15 minutes; (4) effects: (a) capable of prolonging the recalcification time, (b) capable to prolonging the prothrombin iime, (c) capable of prolonging the activated partial thromboplastin time; and (5) amino acid composition as determined by hydrolysis with 5.7 N HCl at 110° C.: ______________________________________ Analysis data Amino acid (mol %) ______________________________________ Aspartic acid 11.0 Threonine 6.1* Serine 5.8* Glutamic acid 12.7 Proline 2.4 Glycine 7.0 Alanine 8.9 1/2 Cystine 0.5 Valine 3.7** Methionine 2.8 Isoleucine 6.2** Leucine 10.0 Tyrosine 3.4 Phenylalanine 3.8 Histidine 1.9 Lysine 7.6 Arginine 6.3 Total 100.0 ______________________________________ in which the unasterisked analysis data are those obtained after the 24-hour hydrolysis, the single-asterisked analysis data are those obtained by extrapolation to 0 hour, and the double-asterisked analysis data are those obtained after the 72-hour hydrolysis.