Effects of ATP on the stability of enzymes against heat treatment in 6-aminonicotinamide treated quail

Abstract

The stabilities of liver and pectoral muscle enzymes in 6-aminonicotinamide (6-AN) treated quail against heat treatment in the presence and absence of added ATP were investigated. Only ATP level in the brain and pectoral muscle of 6-AN treated group was significantly reduced compared to the control group whereas ADP and AMP levels were not affected. In the thermal stability (55 °C) of liver enzymes, the activity of acetylcholinesterase (AChE) was not affected whereas the activities of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and lactate dehydrogenase (LDH) were significantly lowered ( P<0.01). The addition of 1 mM ATP to liver enzyme extracts of 6-AN group afforded 4- and 1.7-fold more protection for GAPDH and LDH, respectively ( P<0.01). In liver, LDH appeared to be more protected by ATP than GAPDH. In muscle, however, GAPDH and AChE activity were significantly affected but not LDH. The addition of 1 mM ATP to muscle enzyme extracts of 6-AN group afforded 1.7-fold more protection for GAPDH ( P<0.01) but rather inactivated AChE. A marked reduction in ATP levels in muscle did not affect specifically muscle enzyme activities only since liver enzyme activities were also affected to the same degree as muscle.