Glutamate: pyruvate aminotransferase

The ADI is a measure of toxicity. It is calculated from a known toxicological effect of a chemical (e.g. pesticide), for example increased serum glutamate pyruvate aminotransferase (SGPT) is often measured as an indicator of liver damage. The dose of the pesticide just below the point at which the defined... 

The alanine released from muscle is taken up by the liver. Glutamate—pyruvate aminotransferase, in liver, catalyzes the conversion of alanine to pyruvate. This pyruvate can then be used for gluconeogenesis. The amino group initially dis-... 

Glutamate-pyruvate aminotransferase Interconversion of alanine and pyruvate... 

Figure 12.7-3. Transamination using glutamic-pyruvic aminotransferase.

Cruickshank and Isherwood (1958) established that wheat germ gluta-materoxaloacetate and glutamate pyruvate aminotransferase activities, which they did not separate, differed in their dependence on supplied PLP and in their response to inhibitors. These investigators therefore proposed that the two activities would turn out to be due to separate enzymes. A study of aspartate and alanine aminotransferase activity in crude pear tissue extracts resulted in a similar prediction (Romani, 1962). This prediction has subsequently been borne out many times in investigations with more highly purified enzymes (see Section III,I). 

BUN, blood urea nitrogen WBC, white blood cell count RBC, red blood cell count GOT, glutamate-oxalacetate aminotransferase GPT, glutamate-pyruvate aminotransferase y-GTP. y-glutamyl transpeptidase. 

Alanine-pyruvate aminotransferase (alanine aminotransferase) and glutamate-a-ketoglutarate aminotransferase (glutamate aminotransferase) catalyze the transfer... 

Glutamate pyruvate transaminase (SGPT), now frequently referred to as alanine aminotransferase (ALT)... 

ALT = alanine aminotransferase (newer name) GPT - glutamate-pyruvate transaminase (older name) AST = aspaitate aminotransferase (newer name) GOT = glutamate-oxaloacetate transaminase (older name)... 

Aminotransferases have received many names as fashions in nomenclature have changed. Two obsolete names are still used in chnical practice glutamate-oxaloacetate transaminase (abbreviated to GOT) is now aspartate aminotransferase, and glutamate-pyruvate transaminase (GPT) is now alanine aminotransferase. The new abbreviations are AST and ALT, respectively. 

This enzyme [EC 2.6.1.2], also known as glutamic-pyruvic transaminase and glutamic-alanine transaminase, catalyzes the pyridoxal-phosphate-dependent reaction of alanine with 2-ketoglutarate, resulting on the production of pyruvate and glutamate. 2-Aminobutanoate will also react, albeit slowly. There is another alanine aminotransferase [EC 2.6.1.12], better known as alanine-oxo-acid aminotransferase, which catalyzes the pyridoxal-phosphate-dependent reaction of alanine and a 2-keto acid to generate pyruvate and an amino acid. See also Alanine Glyoxylate Aminotransferase... 

This enzyme [EC 2.6.1.42], also referred to as transaminase B, catalyzes the reversible reaction of leucine with a-ketoglutarate (or, 2-oxoglutarate) to produce 4-methyl-2-oxopentanoate and glutamate. The pyridoxal-phosphate-dependent enzyme will also utilize isoleucine and valine as substrates. However, this enzyme is distinct from that of valine pyruvate aminotransferase [EC 2.6.1.66]. See also Leucine Aminotransferase... 

ALT alanine transaminase alanine aminotransferase previously known as SGPT (serum glutamate pyruvate transaminase). 

Reaction (20.12) is catalyzed by glutamate-pyruvate transaminase (GPT), also known as alanine aminotransferase, and Equation (20.13) is catalyzed by glutamate dehydrogenase. Note that these reactions are completely reversible. The reverse of deamination, for example, if one wanted to synthesize alanine from ammonia and pyruvate, is amination. 

Alanine + a-ketoglutarate — Pyruvate + Glutamate (alanine aminotransferase)... 

E-7) SGPT (serum glutamate pyruvate transaminase), more recently called ALT (alanine aminotransferase), acts at diis step. Both names make sense, depending on which way you read the chemical reaction. This enzyme is especially concentrated in the liver it leaks out of the liver cell and rises in the serum with liver damage, as in hepatitis and mononucleosis. It does not significantly increase in myocardial infarction and, hence, the test is more specific than SGOT for liver disease. 

No significant difference in levels of serum glutamic-pyruvate transaminase (SGPT, also known as alanine aminotransferase [ALAT]) was observed in six mice (strain not specified) treated once by gavage with 22.5 mg/kg/day 2,4-DNP (Robert 1986). Two dogs repeatedly fed capsules containing... 

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