Mr. Christopher Marang Profile

Christopher Marang

at Univ of Massachusetts Amherst

SPIE Involvement:

Author

Publications (1)

This will count as one of your downloads.

You will have access to both the presentation and article (if available).

DOWNLOAD NOW

This content is available for download via your institution's subscription. To access this item, please sign in to your personal account.

Email or Username Forgot your username?

Password Forgot your password?

Show

Keep me signed in

No SPIE account? Create an account

Proceedings Article | 1 August 2021 Presentation + Paper

Using a single molecule optical trapping assay and FRET to reveal the mechanism of transduction by the molecular motor myosin

Edward Debold, Brent Scott, Chris Marang, Laura Gunther, Christopher Yengo

Proceedings Volume 11798, 1179804 (2021) https://doi.org/10.1117/12.2595724

KEYWORDS: Molecules, Optical tweezers, Fluorescence resonance energy transfer, Data modeling, Molecular lasers, Acquisition tracking and pointing, Silica, Proteins, Molecular interactions, Molecular energy transfer

Read Abstract +

Myosin is biological molecular motor that transduces the chemical energy ATP hydrolysis into force and/or motion to drives many forms of cellular motility from muscle contraction to cell division. While the transduction process has been extensively studied key details remain unclear. Most importantly the timing of the force-generating powerstroke relative to the release of phosphate (Pi), a product of ATP hydrolysis, is not clear and the source of intense debate. We examined the ability of single-headed myosin Va to generate a displacement (i.e. powerstroke) of an actin filament in a kinetic, fluorescent energy transfer (FRET) and single molecule laser trap assays while maintaining Pi in its catalytic site by introducing a mutation that impedes Pi-release from the catalytic site (S217A). Kinetic experiments confirmed that the Pi-release rate was slowed ~5-fold by the S217A substitution, and FRET experiments suggested that the mutation slowed myosin’s rate of attachment to actin. At the single molecule level Wild type myosin Va (WT) generated a 7 nm powerstroke at a rate of ~600/s and the S217A myosin generated a statistically similar size powerstroke (8nm) at a similar rate (600/s) despite impeding the release of Pi from the active site. These findings are consistent with myosin Va generating a powerstroke while Pi is still in the catalytic site, and therefore challenge the hypothesis that Pi-release gates, and therefore precedes, the powerstroke. Our findings imply that myosin’s key mechanical event is triggered by binding to the actin filament, and not by the biochemical event of Pi-release. This provides important new insight into the mechanism of energy transduction by myosin, and evolutionarily related motor proteins.

My Library

You currently do not have any folders to save your paper to! Create a new folder below.

Folder Name

Folder Description

View contact details

UPDATE YOUR PROFILE

Is this your profile? Update it now.

Sign into your SPIE.org account

Don’t have a profile and want one?

Create an account on SPIE.org

Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks. You are receiving this notice because your organization may not have SPIE eBooks access.*

*Shibboleth/Open Athens users─please sign in to access your institution's subscriptions.

To obtain this item, you may purchase the complete book in print or electronic format on SPIE.org.

ORGANIZATIONAL
Sign in with credentials provided by your organization.

Organizational Username

Organizational Password

Show/Hide Password

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available

Members:

Non-members: ADD TO CART

Keywords/Phrases

Search In:

Publication Years