Examination of actin polymerization and viscosity induced by cations and ionic strength when cross-linked by alpha-actinin.
Increasing potassium chloride concentration from 0 to 100 mM and magnesium chloride from 0 to 2 mM show a parallel rate increase in polymerizing actin, whereas increasing calcium chloride concentration from 0 to 0.2 mM decreases the rate of polymerizing actin. The presence of alpha-actinin has little influence on the polymerization kinetics of actin under these conditions. Viscometric measurements indicate that the presence of various mono- and divalent cations, ionic strength, and alpha-actinin in combination are responsible for changes in the mechanical properties of solutions containing actin. The actin filament dynamic behavior is drastically reduced under these conditions as confirmed by quasi-elastic light scattering.
Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA. wgoldmann@partners.org
Wolfgang H
WH
Goldmann
D000185:Actinin / Q000737:chemistry*; D000199:Actins / Q000737:chemistry*; D000818:Animals; D002412:Cations / Q000737:chemistry*; D008027:Light; D015636:Magnesium Chloride / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D011189:Potassium Chloride / Q000737:chemistry; D011485:Protein Binding; D014783:Viscosity
D000199:Actins; D002412:Cations; D011108:Polymers; D015636:Magnesium Chloride; D000185:Actinin; D011189:Potassium Chloride