Structural study on liver gelactin

Electron microscopy, ultracentrifugation, gel filtration, and isoelectric focusing were carried out with gelactin, an actin-gelling protein from rabbit liver. Gelactin is a dimeric acidic protein (isoelectric point (pI) = 5.45), with a molecular weight of 190 000, a Svedberg constant of 6.25, and a Stoke's radius and length of 7.0 and 28 nm, respectively. While different from alpha-actinin by pI and amino acid composition, gelactin belongs by its dimensions to the class of alpha-actinins.