[New findings on an anti-proteinase in human plasma: l'inter-alpha-trypsin inhibitor].
Inter-alpha-trypsin inhibitor (I alpha I) has been purified from C.N.T.S. fraction III as starting material. The purification procedure includes D.E.A.E. cellulose chromatography and gel filtration on G 150 Sephadex in the presence of EDTA. The purified protein gives one precipitation line in immunoelectrophoresis against anti-whole human sérum. It reacts only with an anti I alpha I immune serum and possesses a strong antitryptic activity. When studied in starch or polyacrylamide gel electrophoresis 2 components are observed, each of them having the same antigenic structure and the same antitryptic activity as the crude preparation. The slower and less important component is dissociated by 0,1% SDS. The molecular weight estimation of I alpha I BY PAA/SDS is about 180,000. This result is not modified by the presence of 1% beta mercaptoethanol indicating that I alpha I consists of one polypeptide chain. Crude preparation reveals under the same electrophoretical conditions small amounts of low molecular weight components (135,000 52,000 and 26,000) which can be due to a proteolytic action on I alpha I. Indeed plasmin is able to produce such fragments having an antitryptic activity as shown by fibrin/polyacrylamide gel electrophoresis. The relationship between small molecular weight inhibitors of human serum and bronchial secretions and those obtained after degradation of I alpha I by plasmin is discussed.
D004586:Electrophoresis / Q000379:methods; D000939:Epitopes; D006801:Humans; D008970:Molecular Weight; D010455:Peptides / Q000032:analysis; D000515:alpha 1-Antitrypsin / Q000302:isolation & purification*
D000939:Epitopes; D010455:Peptides; D000515:alpha 1-Antitrypsin
Nouvelles données sur une antiprotéinase du plasma humain: l'inter-alpha-trypsine inhibiteur