CROSS-LINKING OF BETA-HEAVY-CHAIN SUBUNIT OF DYNEIN FROM SEA-URCHIN SPERM FLAGELLA BY DIMETHYL SUBERIMIDATE

The dynein beta heavy chain and the intermediate chain 1 (IC1) from sea urchin sperm flagella cosediment at 11S through sucrose density gradient centrifugation. When the isolated beta/IC1 complex was treated with a bifunctional cross-linker, dimethyl suberimidate (DMS), and analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, four high molecular mass products appeared on the gel. Immunoblotting of the products with affinity-purified polyclonal antibodies against beta heavy chain and IC1 revealed that these were cross-linked products of beta heavy chain and IC1. Treatment of beta/IC1 complex with DMS activated the ATP hydrolysis and decreased its sensitivity to inhibition by vanadate. These results indicate the dynein beta heavy chain and IC1 associate with each other to form a complex and suggest that the intramolecular interactions within beta/IC1 complex are involved in the process of ATP hydrolysis.