a globulin that is present in muscle plasma and that in connection with myosin plays an important role in muscle contraction.
Other definitions for actin- (2 of 2)
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
How to use actin in a sentence
"Oi don't loike th' way he is actin', Frankie," whispered Barney.Frank Merriwell's Bravery | Burt L. Standish
Can't you hear millions spoke of without actin' like a blasted whistlin' buoy?Isle o' Dreams | Frederick F. Moore
And when he quit he went off toward home, slappin' his fists together and actin' as if he didn't see the road across his bows.Cy Whittaker's Place | Joseph C. Lincoln
Ed was actin at Niblo's Garding, which looks considerable more like a parster than a garding, but let that pars.
I don't know what them skunks think they can do, actin' in this way.Motor Matt's Daring Rescue | Stanley R. Matthews
British Dictionary definitions for actin
a protein that participates in many kinds of cell movement, including muscle contraction, during which it interacts with filaments of a second protein, myosin
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Scientific definitions for actin
A protein found in all eukaryotic cells, forming filaments that make up a main component of the cell's supporting matrix or cytoskeleton. Actin and the protein myosin together make up the contractile units (called sarcomeres) of skeletal muscle fibers.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.