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Transamination is a chemical reaction that transfers an amino group to a ketoacid to form new amino acids.This pathway is responsible for the deamination of most amino acids. This is one of the major degradation pathways which convert essential amino acids to non-essential amino acids (amino acids that can be synthesized de novo by the organism).
Tissue transaminase activities can be investigated by incubating a homogenate with various amino/keto acid pairs. Transamination is demonstrated if the corresponding new amino acid and keto acid are formed, as revealed by paper chromatography. Reversibility is demonstrated by using the complementary keto/amino acid pair as starting reactants.
The two reacting molecules are the alpha amino group of one amino acid and the alpha carboxyl group of the other amino acids. A by-product of this bond formation is the release of water (the amino group donates a proton while the carboxyl group donates a hydroxyl).
Surface-based chemical metabolism of amino acids and very small compounds may have led to the build-up of amino acids, coenzymes and phosphate-based small carbon molecules. [ 119 ] [ additional citation(s) needed ] Amino acids and similar building blocks could have been elaborated into proto- peptides , with peptides being considered key ...
Using pyridoxal phosphate (PLP), several N-terminal amino acids can undergo transamination to yield N-terminal aldehyde, such as glycine and aspartic acid (third reaction in Figure 4). An example of C-termini modification is the native chemical ligation (NCL), which is the coupling between a C-terminal thioester and a N-terminal cysteine ...
The amino acids that are produced by protein catabolism can then be further catabolized in amino acid catabolism. Among the several degradative processes for amino acids are Deamination (removal of an amino group), transamination (transfer of amino group), decarboxylation (removal of carboxyl group), and dehydrogenation (removal of hydrogen ...
Tyrosine Aminotransferase as a dimer has two identical active site. Lys280 is attached to PLP, which is held in place via two nonpolar amino acid side chains; phenylalanine and isoleucine (see thumbnail on right). The PLP is also held in place by hydrogen bonding to surrounding molecules mainly by its phosphate group.
Alanine transaminase (ALT), also known as alanine aminotransferase (ALT or ALAT), formerly serum glutamate-pyruvate transaminase (GPT) or serum glutamic-pyruvic transaminase (SGPT), is a transaminase enzyme (EC 2.6.1.2) that was first characterized in the mid-1950s by Arthur Karmen and colleagues. [1]