Studies on the proteinaceous gel secretion from the skin of the catfish, <i>Arius maculatus</i> (Thunberg, 1792)

Abstract

The Catfish Arius maculatus (Thunberg, 1792) causes injury to the fisherman while handling the fish and it was proven that the skin mucus of the fish have several properties including the toxicity. In the present study, the biochemical property of the catfish skin mucus was characterized and it was found that the protein content of the soluble and insoluble fractions were 9.34 and 12.64 ìg/g, respectively. The total lipid was 0.005 ìg/g and the total carbohydrate was 0.08 ìg/g. Of the total 17 amino acids recorded, cysteine availability was very low; 0.01 and 0.02 mole % in the soluble and insoluble fractions, respectively. Leucine was available in high quantity (9.8 mole %) in the soluble fraction and aspartic acid (9.0 mole %) was high in the insoluble fraction. On SDS-PAGE analysis, seven and six bands with a distinct band at 35 KDa in the soluble and insoluble fractions, respectively, were observed. On haemolytic activity, lysis was observed by 50 ìg/ml of insoluble fraction and 25 ìg/ml of soluble fraction. Both soluble and insoluble fractions showed maximum and minimum activities against Escherichia coli and Pseudomonas aueruginosa, respectively.