Bovine aorta actin. Development of an improved purification procedure and comparison of polymerization properties with actins from other types of muscle.
Crude actin extracts from acetone-dried powder of the muscle layer of bovine aorta contain an actin-modulating protein which promotes nucleation of actin monomers and decreases the average length of actin filaments in a Ca2+-dependent manner. This observation has allowed the development of an improved purification procedure for aorta actin which increases the yield 2- to 3-times. The actin obtained with this procedure consists of 77% alpha- and 23% gamma-isoelectric species. Pure aorta actin is indistinguishable from actins from skeletal, cardiac and chicken-gizzard smooth muscle in its polymerization rate, critical concentration, and reduced viscosity when polymerized with KCl at 25 degrees C. It differs from sarcomeric actins, but not from chicken-gizzard smooth muscle actin, in the temperature dependence of polymerization equilibria in KCl. This difference correlates with the amino acid replacements Val-17----Cys-17 and Thr-89----Ser-89, supporting a conclusion drawn from other studies that the N-terminal portion of actin polypeptide chain contains sites important for polymerization.
D000199:Actins / Q000302:isolation & purification* / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D001011:Aorta / Q000032:analysis; D002118:Calcium / Q000378:metabolism; D002417:Cattle; D004492:Edetic Acid / Q000494:pharmacology; D000070559:Gizzard, Non-avian / Q000032:analysis; D007525:Isoelectric Focusing; D008854:Microscopy, Electron; D008970:Molecular Weight; D009131:Muscle, Smooth, Vascular / Q000032:analysis*; D009132:Muscles / Q000032:analysis*; D009206:Myocardium / Q000032:analysis; D011108:Polymers / Q000378:metabolism; D011817:Rabbits
D000199:Actins; D011108:Polymers; D004492:Edetic Acid; D002118:Calcium