[Topography, physicochemical and kinetic properties of the branched amino acid transaminases of the gastric and pancreatic mucosa].

: About 40% of transaminase of branched amino acids were shown to be localized in mitochondrial matrix of pancreatic gland. The transaminases from pancreas and gastric mucosa had pH optima around pH 8.6. The enzymatic activity was increased with an increase in temperature to 50 degrees. In presence of 10 microM concentration of alpha-ketoglutarate Km volume of these two enzymes from postmitochondrial fraction of gastric mucosa and of pancreas were equal to 9.7 . 10(-4)M and 9.0 . 10(-4)M for leucine, 1.1.10(-4) M and 4.10(-3) M for valine, 6.4.10(-4) M and 8.5.10(-4) for isoleucine, respectively. The reaction or transamination proceeded via formation of a substituted form of the enzyme. The transaminase activity was inhibited by capronic acid (I506.8.10(-4) M), valeric acid (I508.10(-4)M), butyric acid (I50 5.8.10(-3) M) and propionic acid (I50 2.10(-2) M).