A novel 27/16 kDa form of subtilisin cleaved actin: structural and functional consequences of cleavage between Ser234 and Ser235.
A new 27/16 kDa form of cleaved actin was prepared by subtilisin cleavage between Ser234 and Ser235 of F(MgADP)-actin complexed with BeFx. The cleavage had little effect on actin-actin interactions as probed in polymerization measurements and by electron microscopy. In circular dichroism melting experiments the thermostability of F-actin was reduced by about 10 degrees C by this cleavage. The in vitro motility and Vmax, but not Km, of actomyosin ATPase were decreased by about 20% upon 27/16 kDa cleavage of F-actin. The binding of tropomyosin to actin was unchanged by this modification.
Vahdat
A
A
Department of Chemistry and Biochemistry, University of California, Los Angeles 90095, USA.
Miller
C
C
Phillips
M
M
Muhlrad
A
A
Reisler
E
E
D000199:Actins / Q000737:chemistry* / Q000378:metabolism* / Q000648:ultrastructure; D000595:Amino Acid Sequence; D000818:Animals; D004355:Drug Stability; D007700:Kinetics; D008854:Microscopy, Electron; D008969:Molecular Sequence Data; D018482:Muscle, Skeletal / Q000378:metabolism; D009218:Myosins / Q000378:metabolism; D010446:Peptide Fragments / Q000302:isolation & purification; D011817:Rabbits; D012694:Serine; D013381:Subtilisins / Q000378:metabolism*
D000199:Actins; D010446:Peptide Fragments; D012694:Serine; D013381:Subtilisins; D009218:Myosins