Affinity modulation in platelet alpha 2 beta 1 following ligand binding

被引:19
作者
GoferDadosh, N
Klepfish, A
Schmilowitz, H
Shaklai, M
Lahav, J
机构
[1] TEL AVIV UNIV,SACKLER FAC MED,IL-69978 TEL AVIV,ISRAEL
[2] KAPLAN MED CTR,HEMATOL UNITE,REHOVOT,ISRAEL
[3] ICHILOV HOSP,TEL AVIV,ISRAEL
关键词
D O I
10.1006/bbrc.1997.6201
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
In order to test for ligand-induced change in the affinity of platelet alpha 2 beta 1 to collagen we passaged labeled viable platelets through a column of fibrillar collagen and used stringent lysis conditions to remove all low-affinity receptors. A high affinity fraction left on the collagen could be eluted with DTT and 2% SDS. Antibodies raised against it Western-blotted alpha 2 beta 1. Functional tests performed with the antibodies confirmed the involvement of the high affinity proteins in platelet-collagen interactions attributed to alpha 2 beta 1: inhibition of collagen-specific platelet adhesion and aggregation. EDTA, chaotropic agents or low pH did not elute the high affinity fraction of cuapl. However, DTT followed by acetic acid did. Our data suggest that 1) ligand binding induces the formation of a new disulfide bond in a fraction of alpha 2 beta 1, 2) that this bond is intrareceptor and 3) that this change increases the affinity of the receptor to its ligand. (C) 1997 Academic Press.
引用
收藏
页码:724 / 727
页数:4
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