1 / 1

The Power Stroke

“Cocked” The ATP pocket closes and the myosin head again changes shape which causes it to move 5nm further down the actin filament ATP hydrolysis occurs, but the products – ADP and Pi – remain tightly bound in the pocket. “Attached” ADP is released during the power stroke

lucien
Download Presentation

The Power Stroke

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. “Cocked” • The ATP pocket closes and the myosin head again changes shape which causes it to move 5nm further down the actin filament • ATP hydrolysis occurs, but the products – ADP and Pi – remain tightly bound in the pocket “Attached” • ADP is released during the power stroke • Myosin is attached in the rigor complex, the ATP pocket is open and waiting for a new cycle to begin The Power Stroke ATP ADP Pi ADP Pi “Force-Generating” • Myosin reattaches to actin (5nm further down the filament than the original site) • Initially, this binding is weak, but the release of Pi causes a conformational change in the head which: • Strengthens the attachment of myosin • Initiates the power stroke Ca “Released” • ATP enters the pocket on the back of the myosin head • This leads to a decrease in the binding affinity for actin, and the myosin head detaches “Attached” • without any energy, the myosin remains attached very tightly to actin • this is the rigor complex and is short lived

More Related