Purification and structural properties of gelsolin, a Ca2+-activated regulatory protein of macrophages.
We describe the purification procedure and some of the physiochemical properties of gelsolin, a major Ca2+-dependent regulatory protein of actin gel-sol transformation in rabbit lung macrophages. Gelsolin accounts for the majority of Ca2+ control of actin gelation in macrophage extracts. It is a single polypeptide chain with an average molecular weight of 91,000 a Stokes radius of 44 A, a sedimentation coefficient (s20(0),w) of 4.9 S, an isoelectric point of 6.1, and a frictional ratio of 1.43. Gelsolin binds 2 mol of Ca2+ with high affinity (Ka 1.09 X 10(6) M-1) in the presence of 0.1 M KCl and 2 mM MgCl2.
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002118:Calcium / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000302:isolation & purification* / Q000378:metabolism; D055598:Chemical Phenomena; D002621:Chemistry; D018260:Gelsolin; D007700:Kinetics; D008264:Macrophages / Q000378:metabolism*; D008970:Molecular Weight; D011485:Protein Binding; D011487:Protein Conformation; D011817:Rabbits
D000596:Amino Acids; D002135:Calcium-Binding Proteins; D018260:Gelsolin; D002118:Calcium