Purification and characterization of N-beta-alanyl-5-S-glutathionyl-3,4-dihydroxyphenylalanine, a novel antibacterial substance of Sarcophaga peregrina (flesh fly).
We purified a novel antibacterial substance from immunized adult Sarcophaga and determined its molecular structure to be N-beta-alanyl-5-S-glutathionyl-3,4-dihydroxyphenylalanine (5-S-GAD). We synthesized 5-S-GAD enzymatically from N-beta-alanyl-3, 4-dihydroxyphenylalanine (beta-Ala-Dopa) and reduced glutathione (GSH). The antibacterial activity of 5-S-GAD was found to be due to its production of H2O2. This is a novel antibacterial mechanism as it differs from the mechanisms of known antibacterial peptides. Two possible roles of 5-S-GAD in insect immunity, suppression of bacterial growth and activation of a Rel family transcription factor, are proposed.
Leem
J Y
JY
Faculty of Pharmaceutical Sciences, University of Tokyo, Bunkyo-ku, Tokyo 113, Japan.
Nishimura
C
C
Kurata
S
S
Shimada
I
I
Kobayashi
A
A
Natori
S
S
D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D004295:Dihydroxyphenylalanine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D004175:Diptera / Q000737:chemistry* / Q000276:immunology / Q000378:metabolism; D004926:Escherichia coli / Q000187:drug effects / Q000276:immunology; D005978:Glutathione / Q000031:analogs & derivatives* / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D006861:Hydrogen Peroxide / Q000378:metabolism; D007114:Immunization; D015394:Molecular Structure
D000900:Anti-Bacterial Agents; C100496:N-beta-alanyl-5-S-glutathionyl-3,4-dihydroxyphenylalanine; D004295:Dihydroxyphenylalanine; D006861:Hydrogen Peroxide; D005978:Glutathione