Directed evolution to probe protein allostery and integrin I domains of 200,000-fold higher affinity.

ABSTRACT: Understanding allostery may serve to both elucidate mechanisms of protein regulation and provide a basis for engineering active mutants. Herein we describe directed evolution applied to the integrin alpha(L) inserted domain for studying allostery by using a yeast surface display system. Many hot spots for activation are identified, and some single mutants exhibit remarkable increases of 10,000-fold in affinity for a physiological ligand, intercellular adhesion molecule-1. The location of activating mutations traces out an allosteric interface in the interior of the inserted domain that connects the ligand binding site to the alpha7-helix, which communicates allostery to neighboring domains in intact integrins. The combination of two activating mutations (F265S/F292G) leads to an increase o

SUBMITTER: Jin M 

PROVIDER: S-EPMC1458646 | biostudies-literature | 2006 Apr

REPOSITORIES: biostudies-literature