Immunochemical properties of the membrane-bound D-lactate dehydrogenase from Escherichia coli

The preparation, characterization, and purification of antibody against the membrane-bound D-lactate dehydrogenase solubilized and purified from Escherichia coli ML 308-225 are described. The antibody is highly specific for the flavin-linked D-lactate dehydrogenase, and incubation of the enzyme with antiserum results in marked inhibition of enzymatic activity. By means of a radioimmune assay, it is demonstrated that membrane vesicles prepared from E. coli ML 308-225dld-3 contain catalytically inactive material which cross-reacts with native D-lactate dehydrogenase. In the following paper, the effects of this antiserum on D-lactate dehydrogenase activity and D-lactate-dependent active transport in native and reconstituted membrane vesicles are examined.