Stabilization of a primary loop in myosin subfragment 1 with a fluorescent crosslinker.

Abstract
A bifunctional fluorescent alkylating agent, dibromobimane, was used to stabilize a preexisting primary loop in myosin subfragment 1 (S-1). The crosslink achieved joins Cys-707 (called SH group "SH1") of the 20-kDa [kilodalton] domain (formerly called "20K" domain) with a thiol of the 50-kDa domain and seems to place the dibromobimane near the ATP-perturabable Try.