Preliminary purification and partial characterization studies of a low-molecular weight cytosolic lead-binding protein in liver of the channel catfish (Ictalurus punctatus)

Abstract

The present study reports the isolation and partial characterization of a lead-binding protein (PbBP) in the liver of the channel catfish ( Ictalurus punctatus). The protein has a molecular weight of 10 kDa as determined by SDS polyacrylamide gel electrophoresis and contains relatively large amounts of glycine (18.3%), aspartic acid (10.2%) and serine (15.1%). Western blot studies conducted using polyclonal antibodies to the rat renal PbBP and metallothionein (MT) showed no cross-reactivity, suggesting that the fish hepatic protein is immunologically distinct from these low-molecular weight metal-binding proteins in mammals.