Thromb Haemost 1991; 65(04): 351-354
DOI: 10.1055/s-0038-1648150
Original Article
Schattauer GmbH Stuttgart

Influence of Tryptophan Modification upon Digestion of Antithrombin III by Elastase

M F Scully
The Thrombosis Research Institute, London, United Kingdom
,
N Shah
The Thrombosis Research Institute, London, United Kingdom
,
V Ellis
The Thrombosis Research Institute, London, United Kingdom
,
V V Kakkar
The Thrombosis Research Institute, London, United Kingdom
› Author Affiliations
Further Information

Publication History

Received: 29 May 1990

Accepted after revision 13 October 1990

Publication Date:
02 July 2018 (online)

Summary

Chemical modification of tryptophan residues in antithrombin III by dimethyl (2-hydroxy-5-nitrobenzyl) sulfonium bromide (HNBSB) generates products with similar levels of modification (equivalent to 0.9 mole 2-hydroxy-5-nitrobenzyl [HNB] incorporated/mole of antithrombin III) but with high or low affinity for heparin-Sepharose. Upon digestion with pancreatic or neutrophil elastase the low affinity forms generate a product of molecular weight form (55 kDa) not seen in digests of native antithrombin III or modified forms with high affinity for heparin. When measured as loss of activity the obserued rate of digestion of the latter in the absence of heparin was more rapid than that of native antithrombin III. The differences in digestion are considered to be related to conformation at differences between the various forms.