Identification of chicken liver mitochondrial alanine:2-oxoglutarate aminotransferase and its response to starvation.
In chicken liver, alanine:2-oxoglutarate aminotransferase was located only in the mitochondria. In 40-day-old chickens, starvation resulted in a dramatic increase of liver mitochondrial alanine:2-oxoglutarate aminotransferase activity, reaching about a 100-fold increase in the activity (units/g of liver) on Day 7 of starvation. The mitochondrial alanine:2-oxoglutarate aminotransferase was purified to homogeneity and characterized from the mitochondrial extract of 7-day-starved chicken liver. The enzyme possessed alanine:glyoxylate aminotransferase activity and was also present in control chicken liver. The enzyme was found in the present study for the first time and named alanine:2-oxoglutarate (glyoxylate) aminotransferase. Alanine:2-oxoglutarate aminotransferase specific for alanine and 2-oxoglutarate as substrates was not detected in both control and starved chicken livers. In contrast, liver mitochondrial alanine:2-oxoglutarate aminotransferase from mammals did not possess alanine:glyoxylate aminotransferase activity. The increase in mitochondrial alanine:2-oxoglutarate aminotransferase activity during starvation was found to be attributed to an increase in enzyme protein.
Fujiwara
S
S
Department of Biochemistry, Kyushu Dental College, Kitakyushu, Japan.
Sakuraba
H
H
Noguchi
T
T
D000612:4-Aminobutyrate Transaminase / Q000302:isolation & purification / Q000378:metabolism*; D000410:Alanine Transaminase / Q000302:isolation & purification / Q000378:metabolism*; D000818:Animals; D002458:Cell Fractionation; D002645:Chickens; D002845:Chromatography; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D017886:Durapatite; D015151:Immunoblotting; D005779:Immunodiffusion; D008099:Liver / Q000201:enzymology*; D008930:Mitochondria, Liver / Q000201:enzymology*; D012016:Reference Values; D013217:Starvation; D013347:Subcellular Fractions / Q000201:enzymology; D013997:Time Factors
D017886:Durapatite; D000612:4-Aminobutyrate Transaminase; D000410:Alanine Transaminase