Reciprocal effects between opioid peptides and human polymorphonuclear leukocytes--I. Chemical modifications of Leu-enkephalin by phorbol myristate acetate-stimulated polymorphonuclear leukocytes.
When L-tyrosyl-glycyl-L-phenylalanyl-L-leucine (Leu-enkephalin) is exposed to the activated oxygen species produced by phorbol myristate acetate (PMA)-stimulated polymorphonuclear leukocytes (PMNs), hydroxylation of the phenylalanyl residue in position 4 of the peptide occurs, producing hydroxy-phenylalanyl derivatives which are identified by HPLC analysis and mass spectrometry. Attack of hydroxyl radicals generated by the Cu (II)/ascorbate system upon Leu-enkephalin also produces isomeric o-, m- and p-hydroxy-phenylalanyl derivatives. When PMNs are incubated with a synthetic peptide, L-tyrosyl-glycyl-glycyl-L-tyrosyl-L-leucine used as a model of hydroxylated Leu-enkephalin, their chemiluminescence response to PMA activation is higher than that of PMNs incubated with Leu-enkephalin.
Slaoui-Hasnaoui
A
A
INSERM U 58, Montpellier, France.
Guerin
M C
MC
Torreilles
J
J
D002851:Chromatography, High Pressure Liquid; D004723:Endorphins / Q000737:chemistry*; D004743:Enkephalin, Leucine / Q000031:analogs & derivatives / Q000737:chemistry*; D006801:Humans; D006900:Hydroxylation; D008163:Luminescent Measurements; D013058:Mass Spectrometry; D009504:Neutrophils / Q000187:drug effects* / Q000378:metabolism; D010455:Peptides / Q000494:pharmacology; D010649:Phenylalanine / Q000031:analogs & derivatives; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D014443:Tyrosine / Q000031:analogs & derivatives / Q000032:analysis
D004723:Endorphins; D010455:Peptides; D014443:Tyrosine; D010649:Phenylalanine; D004743:Enkephalin, Leucine; C020912:N-hydroxytyrosine; C007543:dityrosine; D013755:Tetradecanoylphorbol Acetate