Open AccessOn the Primary Structure of Human Plasminogen and Plasmin
Author(s) -
WIMAN Björn,
WALLÉN Per
Publication year - 1975
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1975.tb02312.x
Subject(s) - cyanogen bromide , plasmin , chemistry , size exclusion chromatography , biochemistry , sialic acid , protein primary structure , amino acid , peptide sequence , chromatography , ion chromatography , peptide , molecular mass , enzyme , gene
Most of the cyanogen bromide fragments obtained from human plasminogen and plasmin have been purified using combinations of gel filtration and ion‐exchange chromatography. The purified fragments have been characterized by molecular weight determination (dodecyl sulphate electropho‐resis), amino acid analysis, carbohydrate analysis and direct NH 2 ‐terminal amino acid sequence determination. Since some of the purified fragments were compounds with uncompletely cleaved methionyl bonds it was possible to clarify the organization of most of the cyanogen bromide fragments in the plasminogen molecule. The fragment containing the arginyl‐valyl bond cleaved during the second step of the activation process is further identified. It is also shown that the micro‐heterogeneity that normally exists in human plasminogen probably has its origin in several sites. One such site is situated in the light (B) chain of plasmin, while another is situated in the carboxy‐terminal part of the heavy (A) chain. Neither of these sites seems to contain sialic acid.