Leucine aminopeptidase in the digestive tract of Dover sole [Solea solea (L.)]

Leucine aminopeptidase from the digestive tract of Dover sole has been shown to have maximum activity at pH 8.3 and at 50°C. The enzyme is activated by manganese ions and inhibited by EDTA. The rate of hydrolysis of leucinamide with uncentrifuged homogenate is four times as fast as when clear supernatant extracts are used. Of the total intestinal leucine aminopeptidase, 42% is present in the midgut, 33% in the foregut and the remainder distributed between stomach, hindgut and rectum. In a study of the effect of inhibitors, TPCK was the most effective, indicating that histidine is probably involved at the active centre. © 1987.