A hyperglycemic peptide hormone from the Caribbean shrimp Penaeus (litopenaeus) schmitti

From a crude extract of the sinus glands of the shrimp Penaeus (litopenaeus ) schmitti a peptide with hyperglycemic activity in a homologous bioassay w as isolated and characterized by a combination of automatic Edman degradati on, enzymatic digestions, TLC of dansyl-amino acids, and mass spectrometry. Its M-r is 8359.4 Da by MS, which coincides with the deduced sequence. Its N-terminus is free and its C-terminus is amidated. It has 6 Cys residues i n conserved positions compared with other known CHI-Is. This is the first s inus gland hormone from an Atlantic Ocean shrimp characterized to date. It has a remarkable 90% sequence similarity to the Indo-Pacific shrimp P. (mar supenaeus) japonicus Pej-VII hyperglycemic hormone. (C) 2000 Elsevier Scien ce Inc. All rights reserved.