Complete amino acid sequence of bovine plasminogen

Abstract

The amino acid sequence of the single polypeptide chain of bovine plasminogen (786 residues, M , 88092) was determined. Cleavage with CNBr yielded 13 fragments of which six originated from cleavage sites different from human plasminogen. Digestion with elastase gave three major fragments: kringles (1 + 2 + 3) and kringle 4, both with intact lysine binding sites, and mini-plasminogen. Subfragmentation was achieved mainly with 2-(2-nitrophenylsulfenyl)-3-methyl-3'-bromoindolenine (BNPS-skatole), Staphylococcus aweus V8 protease and trypsin. The sequences of fragments which were determined by automated Edman degradation, were aligned with overlapping sequences, or, in a few instances, by homology with the known sequence of human plasminogen. Sequence comparison with the human protein showed varying degrees of homology in the different functional and structural domains. The overall identity (78%) is practically the same as that found in those regions corresponding to the heavy (79%) and the light chain (80%) of plasmin. The average degree of identity among the kringles is 83%. Outside the kringle structures the extent of identity decreases, to 65% in the N-terminal region and to about 50% in the connecting strands between the kringles except for the strand between kringles 2 and 3, where only one out of 12 residues is exchanged. The results reported show that bovine plasminogen apparently contains the same structural and functional domains as human plasminogen.

The N‐and O‐linked carbohydrate chains of human, bovine and porcine plasminogen

“…Amino acid sequence analysis revealed that bovine and porcine plasminogen, like the human molecule, both contain two glycosylation sites. The N-glycosidic linkage involving AsnZS9 of BPG and PPG was localized in the corresponding position of kringle 3 ; however, the 0-linked carbohydrate attachment site was shifted to Ser339 in the bovine and to Thr249 in the porcine protein [12,131. In addition, a varying degree of N-glycosylation was found to be responsible for differences in total carbohydrate between the three species investigated in the present study [9].…”

Refolding of bacteriorhodopsin

“…Anilinothiazolinone derivatives were converted to the corresponding phenylthiohydantoins by an automated conversion system and identified by HPLC [27]. …”

Milk protein analysis

“…In blood, Pg is involved in the Iysis of fibrin clot. Blood vessel endothelium synthesizes the tissue Pg-activator (t-PA), a serine proteinase, which is able, by splitting the single peptide bond 557-558, to convert Pg into plasmin, another serine proteinase, consisting of a heavy and a Iight chain linked by 2 disulfide bridges (Schaller et al, 1985). A small proportion of Pg is transferred to milk in which both Pg and plasmin are found in a ratio of ca.…”

“…Plasmin (EG 3.4.21.7) Bovine plasminogen (Pg) is a single-chain blood serum protein composed of 786 amino acid residues with a number of disulfide bridges and 2 carbohydrate moieties (Schaller et al, 1985). In blood, Pg is involved in the Iysis of fibrin clot.…”