PMID- 11309260
OWN - NLM
STAT- MEDLINE
DCOM- 20010719
LR  - 20231105
IS  - 0007-1188 (Print)
IS  - 0007-1188 (Linking)
VI  - 132
IP  - 8
DP  - 2001 Apr
TI  - Selective inhibition of human inducible nitric oxide synthase by 
      S-alkyl-L-isothiocitrulline-containing dipeptides.
PG  - 1876-82
AB  - The aim of this study was to investigate the structure-activity relationship of 
      S-alkyl-L-isothiocitrulline-containing dipeptides towards three partially 
      purified recombinant human nitric oxide synthase (NOS) isozymes, as well as the 
      effects of these compounds on cytokine-induced NO production by human DLD-1 
      cells. In an in vitro assay, S-methyl-L-isothiocitrulline (L-MIT) was slightly 
      selective for human neuronal NOS (nNOS) over the inducible (iNOS) or endothelial 
      (eNOS) isozyme, but the combination of a hydrophobic L-amino acid (L-Phe, L-Leu 
      or L-Trp) with L-MIT dramatically altered the inhibition pattern to give 
      selective iNOS inhibitors. Introduction of a hydroxy, nitro, amino or methoxy 
      group at the para position of the aromatic ring of L-MIT-L-Phe (MILF) decreased 
      the selectivity and inhibitory potency. A longer or larger S-alkyl group also 
      decreased the selectivity and potency. Dixon analysis showed that all of the 
      dipeptides were competitive inhibitors of the three isoforms of human NOS. The 
      enzymatic time course curves indicated that MILF was a slow binding inhibitor of 
      human iNOS. These results suggest that the human NOS isozymes have 
      different-sized cavities in the binding site near the position to which the 
      C-terminal of L-arginine binds, and the cavity of iNOS is hydrophobic. 
      Interestingly, L-MIT-D-Phe (MIDF) showed little inhibitory activity or 
      selectivity, suggesting that the cavity of human iNOS is located in a 
      well-defined direction from the alpha carbon atom. NO production in 
      cytokine-stimulated human DLD-1 cells was measured with a fluorescent indicator, 
      DAF-FM. MILF, L-MIT-L-Trp(-CHO) (MILW) and L-MIT-L-Tyr (MILY) showed more potent 
      activity than L-MIT in this whole-cell assay. Thus, 
      S-alkyl-L-isothiocitrulline-containing dipeptides are selective inhibitors of 
      human iNOS, and work efficiently in cell-based assay.
FAU - Park, J M
AU  - Park JM
AD  - Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, 
      Bunkyo-ku, Tokyo 113-0033, Japan.
FAU - Higuchi, T
AU  - Higuchi T
FAU - Kikuchi, K
AU  - Kikuchi K
FAU - Urano, Y
AU  - Urano Y
FAU - Hori, H
AU  - Hori H
FAU - Nishino, T
AU  - Nishino T
FAU - Aoki, J
AU  - Aoki J
FAU - Inoue, K
AU  - Inoue K
FAU - Nagano, T
AU  - Nagano T
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - England
TA  - Br J Pharmacol
JT  - British journal of pharmacology
JID - 7502536
RN  - 0 (Cytokines)
RN  - 0 (Dipeptides)
RN  - 0 (Enzyme Inhibitors)
RN  - 0 (Recombinant Proteins)
RN  - 29VT07BGDA (Citrulline)
RN  - 31C4KY9ESH (Nitric Oxide)
RN  - EC 1.14.13.39 (NOS2 protein, human)
RN  - EC 1.14.13.39 (Nitric Oxide Synthase)
RN  - EC 1.14.13.39 (Nitric Oxide Synthase Type II)
SB  - IM
MH  - Citrulline/*analogs & derivatives/*pharmacology
MH  - Cytokines/pharmacology
MH  - Dipeptides/*pharmacology
MH  - Enzyme Inhibitors/*pharmacology
MH  - Humans
MH  - Kinetics
MH  - Nitric Oxide/biosynthesis
MH  - Nitric Oxide Synthase/*antagonists & inhibitors
MH  - Nitric Oxide Synthase Type II
MH  - Quantitative Structure-Activity Relationship
MH  - Recombinant Proteins
MH  - Tumor Cells, Cultured
PMC - PMC1572740
EDAT- 2001/04/20 10:00
MHDA- 2001/07/20 10:01
PMCR- 2002/04/01
CRDT- 2001/04/20 10:00
PHST- 2001/04/20 10:00 [pubmed]
PHST- 2001/07/20 10:01 [medline]
PHST- 2001/04/20 10:00 [entrez]
PHST- 2002/04/01 00:00 [pmc-release]
AID - 0704023 [pii]
AID - 10.1038/sj.bjp.0704023 [doi]
PST - ppublish
SO  - Br J Pharmacol. 2001 Apr;132(8):1876-82. doi: 10.1038/sj.bjp.0704023.