Racemization of Amino Acids by Lower Fatty Acids.

Racemization of Meteoritic Amino Acids

Meteorites may have contributed amino acids to the prebiotic Earth, affecting the global ratio of right-handed to left-handed (D/ L) molecules. We calculate D/ L ratios for seven biological, α-hydrogen, protein amino acids over a variety of plausible parent body thermal histories, based on meteorite evidence and asteroid modeling. We show that amino acids in meteorites do not necessarily underg...

Racemization of amino acids in marine sediments.

Isoleucine, one of several amino acids isolated from a suite of welldated deep-sea cores, shows a progressive increase in the degree of racemization with the age of the sediment. Amino acids in sediments show an initial rate of racemization almost an order of magnitude faster than the rate observed for free amino acids at a comparable pH and temperature. The observed kinetics depend on a variet...

Correction: Abiotic Racemization Kinetics of Amino Acids in Marine Sediments

The ratios of d- versus l-amino acids can be used to infer the sources and composition of sedimentary organic matter. Such inferences, however, rely on knowing the rates at which amino acids in sedimentary organic matter racemize abiotically between the d- and the l-forms. Based on a heating experiment, we report kinetic parameters for racemization of aspartic acid, glutamic acid, serine, and a...

Fatty Livers Induced by Amino Acids and Influence of Other Amino Acids on Them.

It was found by Beeston et al.(1) that fatty liver is induced in the rat by giving a choline-deficient diet supplemented with cystine and the development of this fatty liver is prevented by the administration of choline. Supplementation of the diete with methionine has also been known to have a preventive effect on this fatty liver12>. Although methionine is an essential amino acid and is requi...

Response of laying hens to supplementation with various fatty acids when fed diets inadequate in protein and sulphur amino acids