Tissue transaminase activities in the black-sea mollusc Mytilus galloprovincialis Lam. with different shell color

Abstract

The tissue activities of aspartate aminotransferase (AST, EC 2.6.1.1) and alanine aminotransferase (ALT, EC 2.6.1.2) were studied in the bivalve molluscs differing in shell color. The shell color patterns were evaluated by photographing and computer image processing in Adobe Photoshop CS-3. The transaminase activities were determined by the Reitman-Frankel method. The four shell-color groups of molluscs were distinguished: black, intermediate, dark- and light brown. The AST and ALT activities were found to increase as shell color became lighter, probably reflecting different tolerance of molluscs to habitats with different oxygen concentration. The ALT distribution pattern differed appreciably in the foot of M. galloprovincialis where the highest values were found in the black-colored mussels, apparently due to the change of the predominant enzyme function. In this tissue, the transamination reaction was directed towards replenishing the pool of free amino acids required for the synthesis of byssus filaments.