标题：An isolated, surface-expressed I domain of the integrin αLβ2 is sufficient for strong adhesive function when locked in the open conformation with a disulfide bond
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2001
卷号：98
期号：5
页码：2387-2392
DOI：10.1073/pnas.041606398
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：We introduced disulfide bonds to lock the integrin L{beta}2 I domain in predicted open, ligand binding or closed, nonbinding conformations. Transfectants expressing L{beta}2 heterodimers containing locked-open but not locked-closed or wild-type I domains constitutively adhered to intercellular adhesion molecule-1 (ICAM-1) substrates. Locking the I domain closed abolished constitutive and activatable adhesion. The isolated locked-open I domain bound as well as the activated L{beta}2 heterodimer, and binding was abolished by reduction of the disulfide. Lovastatin, which binds under the conformationally mobile C-terminal -helix of the I domain, inhibited binding to ICAM-1 by L{beta}2 with wild-type, but not locked-open I domains. These data establish the importance of conformational change in the L I domain for adhesive function and show that this domain is sufficient for full adhesive activity.
