Carbohydrate isoforms of antithrombin variant N135Q with different heparin affinities

FEBS Letters

Fan, Bingqi¹  Gettins, Peter G.W.¹  Turko, Illarion V.¹ 

[1]Department of Biochemistry and Center in Molecular Toxicology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA

关键词: Antithrombin;    Site-directed mutagenesis;    Variant;    Carbohydrate;    Glycosylation;    Heparin affinity;    BHK;    baby hamster kidney;    HAT;    human antithrombin;    N135Q;    variant of antithrombin in which Asp-135 has been changed to glutamine;    forms I;    II;    and III represent differently glycosylated forms of wild-type recombinant human antithrombin with low;    intermediate;    and high affinities for heparin;    HAH;    high affinity heparin;   

DOI  :  10.1016/0014-5793(93)80429-X

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

We have changed one of the carbohydrate-bearing asparagine residues of human antithrombin to glutamine by site-directed mutagenesis and expressed the variant antithrombin, N 135Q, in baby hamster kidney cells. Two isoforms were secreted, both of which had higher affinity for heparin than human plasma α antithrombin. Both forms had normal inhibitory activity toward factor X_a and showed normal heparin acceleration of proteinase inhibition. The mutation resulted in a higher production of the very high affinity form from about 30% to 60% of the total secreted antithrombin. This form should be the most useful for comparison of the effects of other mutations on heparin binding and proteinase inhibition.

【 授权许可】

Unknown