Involvement of dehydroalanine and dehydrobutyrine in the addition of glutathione to nisin.
Nisin variants and fragments were reacted with glutathione, and the products of the reactions were analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and liquid chromatography/mass spectrometry (LC-MS). Reactions between glutathione and either [Ala5]nisin or [Ala33]nisin resulted in products with two glutathione molecules conjugated to one nisin variant molecule. Only one glutathione molecule was added to [Ala5,Ala33]nisin. Fragmentation of the nisin molecule resulted in nisin 1-12, nisin 1-20, and nisin 1-32 fragments. Each fragment retained two dehydro residues, which subsequently underwent reaction with glutathione. The data indicated that the dehydroalanine residues of nisin are sites of addition for glutathione. Such addition renders the nisin molecule inactive.
Rose
Natisha L
NL
Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta T6G 2P5, Canada.
Sporns
Peter
P
Dodd
Helen M
HM
Gasson
Mike J
MJ
Mellon
Fred A
FA
McMullen
Lynn M
LM
D000409:Alanine / Q000031:analogs & derivatives* / Q000737:chemistry*; D000595:Amino Acid Sequence; D000613:Aminobutyrates / Q000737:chemistry*; D000900:Anti-Bacterial Agents / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D005520:Food Preservatives / Q000737:chemistry*; D005978:Glutathione / Q000737:chemistry*; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D009561:Nisin / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D000613:Aminobutyrates; D000900:Anti-Bacterial Agents; D005520:Food Preservatives; D009561:Nisin; C088694:dehydrobutyrine; C015102:dehydroalanine; D005978:Glutathione; D000409:Alanine