한우의 악하선에 있는 branched-chain아미노산 aminotransferase [EC 2.6.1.6]의 분포 및 isozyme의 pattern을 관찰하였다. 효소의 활성도는 Ichihara and Koyama의 방법으로 측정하였으며 isozyme은 ammonium sulfate에 의한 침전 및 DEAE-cellulose column chromatography에 의하여 분리하였다. 이상과 같이 하여 다음과 같은 결론을 얻었다. 1. 악하선의 branched-chain amino acid aminotransferase 활성도는 흰쥐의 정상조직인 심장, 장관 및 췌장에 비하여 낮았다. 2. BCAT는 세포질, mitochondria 및 핵분획에서 발견되며, 세포질에 약 85%, mitochondria에 약 8%, 핵분획에 약 6%가 분포되어 있었다. 3. 기질에 대한 효소활성도는 L-leucine이 가장 높았다. 4. 세포질에 있는 이 효소를 부분 정제하여 isozyme의 pattern을 관찰하기 위하여 DEAE-cellulose column chromatography를 행한 결과 용출액인 인산염 완충액의 농도가 20mM에서 Enzyme I 만이 검출되었다. 5. 소의 악하선에는 BCAT의 isozyme인 Enzyme II 및 III은 발견할 수 없었다.
The activity and isozyme pattern of branched-chain amino acid aminotromsferase (EC 2.6.1.6) in bull submaxillary gland have been studied. The activity of branched-chain amino acid aminotransferase was measured by the method of Ichihara and Koyama. Isozyme pattern of this enzyme was also examined by using of DEAE-cellulose column chromatography. The results obtained were as follows; 1. In the bull submaxillary gland, the aminotransferase activities for branched-chain amino acids are relatively low compared with those in rat tissues, i, e., intestine, pancreas, and heart. 2. This enzyme was localized in the cytosolic, mitochondrial and nucleic fraction. About 85% of the total activity was found in the cytosolic fraction, 8% in the mitochondrial fraction and 6% in the nucleic fraction. 3. Cytosolic fraction of bull submaxillary gland contained Enzyme I, but not Enzyme II and III, of branched chain amino acid aminotransferase Enzyme I was eluted by 20mM phosphate buffer from DEAE-cellulose column and catalyzed the transamination of all three branched-chain amino acids, 4. The chromatographic elution profile of the Enzyme I from the bull submaxillary gland was very similar with those of normal rat liver and brain.
