Presence of intestinal, liver and heart adipocyte fatty-acid-binding protein types in the liver of a chimaera fish

Five fatty-acid-binding proteins from the liver of the elephant fish (Callo rhynchus callorhynchus), a chimaera fish that belongs-together with the ela smobranchs-to the ancient chondrichthyes class were isolated and characteri zed. The purification procedures for these proteins involved gel filtration , anion-exchange chromatography, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis as a last step. They were submitted to "in gel" tryptic or cyanogen bromide digestion and the resulting peptides were separated by high performance liquid chromatography and then sequenced by Edman degrada tion. According to their partial amino acid sequences, one of them presents the highest identity with fatty-acid-binding proteins from human and catfi sh liver, another three with those from mammalian heart or adipose tissue a nd the fifth with the mammalian intestinal fatty-acid binding protein. The presence of various members of this protein family, as now found in elephan t fish and previously in catfish (Rhamdia sapo) liver, does not occur in ma mmalian liver which expresses only one a characteristic fatty-acid-binding protein. (C) 1998 Elsevier Science Ltd. All rights reserved.