title: Purification and partial characterization of a D-like fragment from human fibrinogen, produced by human leukocyte elastase.
abstract: Digestion of human fibrinogen with human leukocyte elastase in the presence of Ca2+ yields a D-like fragment of Mr 93000. This fragment was purified by gel filtration on Sephacryl S-200 followed by chromatofocusing. The purified fragment was partially characterized and compared with a fragment termed D-cate, which is produced by plasmin digestion of fibrinogen in the presence of Ca2+. The molecular weights of the constituent chains of the D-like fragment and D-cate were similar. The D-like fragment precipitated with antisera directed against D-cate, but not with antisera against fragment E. The name D-elastase for the fragment is suggested. Differences between the D-elastase and D-cate fragments were found in amino-terminal amino acids, in isoelectric point and in the expression of D antigenic determinants. Two major functional differences were demonstrated: fragment D-elastase had a much stronger anticlotting potency than D-cate and the binding of Ca2+ by D-elastase and D-cate differed qualitatively and quantitatively. Since it has been suggested that the calcium-binding and anticlotting properties of D-cate are related to a carboxyl-terminal 13000 stretch of the gamma-chain, the present findings for D-elastase indicate that the differences in these properties between D-cate and D-elastase are due to differences in this area of the molecule.
mesh_terms: D002118:Calcium / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D005338:Fibrin Fibrinogen Degradation Products / Q000302:isolation & purification*; D005340:Fibrinogen / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D008970:Molecular Weight; D009504:Neutrophils / Q000201:enzymology*; D010196:Pancreatic Elastase / Q000097:blood*; D011485:Protein Binding
chemical_list: D005338:Fibrin Fibrinogen Degradation Products; C015214:fibrinogen D fragment; D005340:Fibrinogen; D010196:Pancreatic Elastase; D002118:Calcium