ABSTRACT
Homogenates of fat-body of Schistocerca gregaria Forsk. were shown to catalyse transamination reactions between α-ketoglutarate and. numerous α-amino acids. The aspartate/glutamate and alanine/ghitamate transaminases were the most active. They were present in both the ‘soluble ‘and the mitochondrial fractions of fat-body cells and also in Malpighian tubules and mid-gut wall. The other transaminases in the fat-body were confined to the mitochondrial fraction.
Fat-body, Malpighian tubule and mid-gut wall homogenates were able to convert glutamic acid into glutamine, a compound which could also act as an amino-group donor in some transamination reactions.
A glutamate-cytochrome c reductase system which involved diphosphopyridine nucleotide was present in fat-body.
Fat-body contained an active arginase, but urease could not be detected. A D-amino-acid oxidase was present, together with a less active L-amino-acid oxidase.
In general, it appears that amino-acid metabolism in the locust resembles that in higher animals.
