Primary structure and reactive site of Streptoverticillium anticoagulant (SAC), a novel protein inhibitor of blood coagulation produced by Streptoverticillium cinnamoneum subsp. cinnamoneum.
The complete amino acid sequence of SAC I, a novel protein inhibitor of blood coagulation produced by Streptoverticillium cinnamoneum subsp. cinnamoneum IFO 12852, was determined. Automated Edman degradation was employed for its fragment peptides, which were obtained by specific cleavage procedures including tryptic, chymotryptic, and peptic digestions, and cyanogen bromide treatment. SAC I is composed of 110 amino acid residues with a molecular weight of 11,642. It has two intramolecular disulfide bonds, Cys31-Cys46 and Cys68-Cys98, but no cysteine residues. The overall sequence homology of SAC I is 58% to plasminostreptin, a protein protease inhibitor produced by Streptomyces antifibrinolyticus, and 52% to S-SI, Streptomyces subtilisin inhibitor, produced by Streptomyces albogriseolus. Subtilisin [EC 3.4.21.14]-modified SAC I, which was prepared by incubating SAC I with subtilisin, had a newly-generated amino terminal sequence, Glu71-Trp72-Asn73-, in addition to the original amino terminal sequence, and a newly-generated carboxyl terminal arginine in addition to the original phenylalanine. These results clearly show that the Arg70-Glu71 bond was specifically cleaved on the limited proteolysis with subtilisin and that the bond is the relative site for subtilisin.
Tanabe
M
M
Research Division, Nihon Pharmaceutical Co., Ltd., Chiba.
Kawahara
K
K
Asano
T
T
Kato
K
K
Kakinuma
A
A
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000737:chemistry*; D001665:Binding Sites; D001779:Blood Coagulation Factors / Q000037:antagonists & inhibitors*; D002918:Chymotrypsin; D003488:Cyanogen Bromide; D003553:Cystine / Q000032:analysis; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry; D010449:Peptide Mapping; D017386:Sequence Homology, Amino Acid; D013306:Streptomycetaceae / Q000737:chemistry; D013329:Structure-Activity Relationship; D014357:Trypsin
D001426:Bacterial Proteins; D001779:Blood Coagulation Factors; D010446:Peptide Fragments; C089436:anticoagulant protein, Streptomyces cinnamoneus; D003553:Cystine; D002918:Chymotrypsin; D014357:Trypsin; D003488:Cyanogen Bromide