AN ELEVATED GLUTATHIONE-S-TRANSFERASE IN CREOSOTE-RESISTANT MUMMICHOG(FUNDULUS-HETEROCLITUS)

A population of mummichog (Fundulus heteroclitus) inhabit a site (Atla ntic Wood) in the Elizabeth River, VA, heavily contaminated with creos ote. Although chronic effects including hepatic neoplasms have been ob served in adult mummichog, these fish are resistant to the acute effec ts (mortality within a few days of exposure) of the creosote-contamina ted sediments while fish from a reference site are not, Increased leve ls and activity of glutathione S-transferases (GST) in Atlantic Wood f ish may play a role in this resistance, In the present study? hepatic GSTs from Atlantic Wood and reference site fish were isolated by S-hex ylglutathione affinity chromatography. A monoclonal antibody was produ ced that recognizes a GST that is elevated approximately six-fold in A tlantic Wood fish and two-fold in fish from a moderately contaminated site relative to fish from the reference site. GST activity towards 1- chloro-2,4-dinitrobenzene was elevated approximately four-fold and two -fold in these fish relative to fish from the reference site. The elev ated GST has a molecular mass of approximately 27.2 kDa and isoelectri c point of 8.1. The N-terminus of the isoform was blocked, preventing N-terminal amino acid determination. (C) 1998 Elsevier Science B.V. Al l rights reserved.