Naslov
Selective determination of fish aspartate aminotransferase isoenzymes by their differential sensitivity to proteases

Autori
Petrović, Siniša ; Semenčić, Lorena ; Ozretić, Bartolo ; Krajnović-Ozretić, Mirjana

Izvornik
Comparative biochemistry and physiology. Part B, Biochemistry & molecular biology (1096-4959) 124 (1999), 1; 209-214

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
aspartate aminotransferase(AAT) ; chymotrypsin ; cytosolic AAT ; enzyme inactivation ; fish plasma

Sažetak
Various proteases (proteinase K, subtilisin, trypsin and chymotrypsin) were used to study the selective inactivation of the aspartate aminotransferase (EC 2.6.1.1) isoenzymes of grey mullet (Mugil auratus Risso ; Osteichthyes). The cytosolic isoenzyme was significantly inactivated by proteinase K, subtilisin and chymotrypsin, while the mitochondrial isoenzyme was sensitive only to proteinase K and to high doses of trypsin. Further identification of the aspartate aminotransferase isoenzymes was based on their discrete sensitivity toward chymotrypsin. Chymotrypsin (1 mg/ml) successfully inhibited purified cytosolic aspartate aminotransferase as well as cytosolic isoenzyme from plasma, whereas the mitochondrial form persisted unaffected. Similar results were obtained when examining liver and red muscle homogenates. This method revealed that the increased total activity of aspartate aminotransferase in fish plasma with induced acute liver injury, was partially a result of the mitochondrial isoenzyme leakage from damaged tissue

Izvorni jezik
Engleski

Znanstvena područja
Biologija

POVEZANOST RADA