Leucine and glutamine were used to elicit biphasic insulin release in rat pancreatic islets. Leucine did not mimic the full biphasic response of glucose. Glutamine was without effect. However, the combination of the two did mimic the biphasic response. When the ATP-sensitive K+ (KATP) channel-independent pathway was studied in the presence of diazoxide and KCl, leucine and its nonmetabolizable ...

Abstract NADH-dependent phenylalanine amine dehydrogenase (F-AmDH) engineered from (PheDH) catalyzes the synthesis of aromatic chiral amines prochiral ketone substrates. However, its low coenzyme affinity and catalytic efficiency limit industrial application. Here, we developed a chimeric dehydrogenase, cFLF-AmDH, based on relative independence structure at domain level, combined with substrate...

We created a novel chimeric amine dehydrogenase (AmDH) via domain shuffling of two parent AmDHs ('L- and F-AmDH'), which in turn had been generated from leucine and phenylalanine DH, respectively. Unlike the parent proteins, the chimeric AmDH ('cFL-AmDH') catalyzes the amination of acetophenone to (R)-methylbenzylamine and adamantylmethylketone to adamantylethylamine.

Purified bovine liver branched chain ketoacid dehydrogenase is inhibited by its reaction products, NADH and the branched chain acyl-CoA thiol esters. This provides an immediate, short term regulation mechanism for this enzyme which commits leucine, isoleucine, and valine to the catabolic pathway. We find that clofibric acid (p-chlorophenoxymethylpropionic acid) and phenylpyruvate also specifica...

Two types of Pseudomonas putida PpG2 mutants which were unable to degrade branched-chain amino acids were isolated after mutagenesis and selection for ability to grow on succinate, but not valine, as a sole source of carbon. These isolates were characterized by growth on the three branched-chain amino acids (valine, isoleucine, and leucine), on the corresponding branched-chain keto acids (2-ket...

Starvation or feeding rats on a high-protein diet, valine or isoleucine, but not leucine, increases the activity of muscle phosphoenolpyruvate carboxykinase, but has no effect on NADP+-linked malate dehydrogenase. This suggests that muscle phosphoenolpyruvate carboxykinase is involved in oxidation or conversion of some amino acids to alanine.

The effect of Musa paradisiaca stem kernel juice was investigated in experimental urolithiatic rats. Stone forming rats exhibited a significant elevation in the activities of two oxalate synthesizing enzymes - Glycollic acid oxidase and Lactate dehydrogenase. Deposition and excretion of stone forming constituents in kidney and urine were also increased in these rats. The enzyme activities and t...

Fructose diphosphate aldolase and glyceraldehyde 3-phosphate dehydrogenase have been crystallized from rabbit livers after single or sequential injections of [‘“Cland (3H]lysine. The specific radioactivity of the lysine in the dehydrogenase rises continuously and reaches a maximum during the 5th day after injection, whereas that of the aldolase declines exponentially from the middle of the 1st ...

The effects of tumor necrosis factor-α (TNF-α; cachectin) and lipopolysaccharide of Salmonella enteritidis (LPS; endotoxin) on leucine metabolism in rats were evaluated in the whole body using intravenous infusion ofl-[1-14C]leucine and in isolated perfused liver (IPL) using the single-pass perfusion technique with α-keto[1-14C]isocaproate as a tracer for measurement of ketoisocaproic acid (KIC...