Molecular cloning, cDNA sequencing, and chemical synthesis of cecropin B from Hyalophora cecropia.
Two cDNA clones containing coding information for cecropin B from the Cecropia moth (Hyalophora cecropia) were identified by means of a synthetic probe. Sequencing of the two inserts showed that cecropin B is processed from a 62-amino acid residue precursor molecule including a 26-residue leader peptide and a COOH-terminal glycine residue. The latter presumably donates the nitrogen of the amide group present on the COOH-terminal leucine residue of the mature cecropin B. The sequence deduced for the mature cecropin B differed in the COOH-terminal region from the tentative structure previously determined by carboxypeptidase digestion. To settle the discrepancy, cecropin B was synthesized according to the cDNA sequence with an amidated COOH-terminal leucine. Natural and synthetic cecropin B were found to be indistinguishable with respect to electrophoretic mobility and antibacterial activity against seven different bacteria. The COOH-terminal tetrapeptides were isolated from both natural and synthetic cecropin B and found to be indistinguishable. The correct sequence for cecropin B is (formula; see text).
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D007301:Insect Hormones / Q000138:chemical synthesis / Q000235:genetics*; D019476:Insect Proteins; D007915:Lepidoptera / Q000235:genetics*; D009036:Moths / Q000235:genetics*; D011499:Protein Processing, Post-Translational
D007301:Insect Hormones; D019476:Insect Proteins; C031162:cecropin B protein, Insecta; D004247:DNA