COMPLETE AMINO-ACID-SEQUENCE OF CROCODILE GROWTH-HORMONE

This paper describes the isolation and complete amino acid sequence of growth hormone (GH) from the pituitary gland of the crocodile, Crocod ylus novaeguineae. GH was detected in an alkaline extract of the pitui tary by specific immunoblot reactivity with rabbit antisera against ca ttle and salmon GH and isolated in pure form by DEAE-cellulose chromat ography and by reversed-phase high-performance liquid chromatography. The yield of the GH was 2.2 mg from 3.5 g of wet tissue. Crocodile GH consists of 190 residues and is highly similar to chicken, duck, and s ea turtle GHs with 90-92% structural similarity, although it shows onl y 27% identity with crocodile prolactin. A molecular phylogenetic tree of GR from 39 vertebrate species is proposed on the basis of sequence comparison. (C) 1995 Academic Press, Inc.