Open AccessOn the interaction of bovine seminal RNase with actin in vitro
Author(s) -
SIMM Franz C.,
KRIETSCH Wolfgang K. G.,
ISENBERG Gerhard
Publication year - 1987
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1987.tb13482.x
Subject(s) - rnase p , actin , ribonuclease , polymerization , depolymerization , chemistry , bovine pancreatic ribonuclease , actina , actin binding protein , biophysics , biochemistry , biology , actin cytoskeleton , cytoskeleton , rna , polymer chemistry , polymer , cell , organic chemistry , gene
Ribonuclease from bovine seminal plasma (RNase BS) interacts with skeletal muscle actin in the following way: it (1) binds to actin with an apparent binding constant of 9.2 × 10 4 M −1 in 0.1 M KCl, (2) induces the polymerization of actin below the critical concentration in depolymerization buffer, (3) accelerates the salt‐induced polymerization of actin even at a molar ratio of RNase to actin lower than 1/100, and (4) bundles F‐actin filaments. In the bundles the molar ratio of RNase to actin is about 0.66. (5) Actin inhibits the enzymatic activity of RNase BS. RNase A from bovine pancreas, which is structurally almost identical to the subunits of RNase BS as well as a monomeric form of RNase BS, do not cross‐link actin filaments and have a much smaller effect on the polymerization of actin. We conclude that the dimeric structure of the RNase BS, which consists of two identical subunits cross‐linked by interchain disulfide bridges, is probably responsible for the bundling activity and the accelerating effect on the polymerization of actin.