title: Isolation of a new actin-gelling protein from liver.
abstract: An F-actin crosslinking protein, tentatively named gelactin, has been isolated from rabbit liver. This protein is a dimer of 200 000 molecular weight which promotes the lateral association of actin filaments. The effect is maximal at a molar ratio of gelactin:actin of about 1:1000. The dependency of the gelation process on various experimental factors was studied by a centrifugation assay. The results demonstrate that gelation is greatly influenced by pH, ionic strength and temperature, but is insensitive to the presence of calcium ions. We show that, in our conditions, the association of actin with gelactin does not interfere with actin-myosin interactions and does not influence the kinetics of actin polymerization. The amino acid composition of gelactin is also given. From its overall properties gelactin is shown to be different from all other actin-gelling proteins.
mesh_terms: D000199:Actins; D000596:Amino Acids; D000818:Animals; D002352:Carrier Proteins; D055598:Chemical Phenomena; D002621:Chemistry; D008099:Liver / Q000032:analysis*; D046911:Macromolecular Substances; D008840:Microfilament Proteins; D008970:Molecular Weight; D011506:Proteins / Q000302:isolation & purification*; D011817:Rabbits; D014783:Viscosity
chemical_list: D000199:Actins; D000596:Amino Acids; D002352:Carrier Proteins; C034037:F-actin-binding proteins; D046911:Macromolecular Substances; D008840:Microfilament Proteins; D011506:Proteins