PROTEIN-PURIFICATION AND CDNA CLONING OF A CECROPIN-LIKE PEPTIDE FROMTHE LARVAE OF FALL WEBWORM (HYPHANTRIA-CUNEA)

A proteinous antimicrobial substance was purified from the bacteria-ch allenged larvae of the fall webworm, Hyphantria cunea. It is a cecropi n-like antibacterial peptide which exhibits antibacterial activity aga inst Gram-negative and Gram-positive bacteria, and known as Hyphantria cecropin A. The cDNA clones corresponding to this peptide were isolat ed from a cDNA library constructed from the bacteria-challenged larvae and obtained complete nucleotide sequences. In addition to the Hyphan tria cecropin A sequence, we obtained three other cDNAs exhibiting hig h sequence similarity with Hyphantria cecropin A. We synthesized the C -terminally amidated peptide of 35 residues based on the deduced seque nce of the isolated cDNA of Hyphantria cecropin A. The synthetic pepti de exhibited strong antibacterial activity against several microbes in cluding medically important bacteria such as Salmonella, Shigella, and fungus such as Candida, A Southern blot experiment using these cloned cDNAs as probes predicted the existence of multiple forms of Hyphantr ia cecropin genes. (C) 1997 Elsevier Science Ltd, All rights reserved.