PMID- 7690590
OWN - NLM
STAT- MEDLINE
DCOM- 19931020
LR  - 20190613
IS  - 0006-2960 (Print)
IS  - 0006-2960 (Linking)
VI  - 32
IP  - 37
DP  - 1993 Sep 21
TI  - NG-methyl-L-arginine functions as an alternate substrate and mechanism-based 
      inhibitor of nitric oxide synthase.
PG  - 9677-85
AB  - NG-Methyl-L-arginine (L-NMA) is one of the most commonly used inhibitors of the 
      nitric oxide synthases (NOS). Results reported here demonstrate that L-NMA is an 
      alternate substrate and a mechanism-based inhibitor of the inducible NOS purified 
      from murine macrophages. The irreversible inhibition displays pseudo-first-order 
      kinetics of inactivation with kinact = 0.07 min-1 and KI = 2.7 microM. 
      Inactivation of NOS is enantiospecific for L-NMA, and substrate protection 
      against inactivation is enantiospecific for L-arginine. L-NMA is hydroxylated, 
      producing NG-hydroxy-NG-methyl-L-arginine (L-NHMA), and both compounds are slow, 
      partially uncoupled alternate substrates for NOS. Processing of L-NMA by NOS 
      results in four amino acid products: L-NHMA, NG-hydroxy-L-arginine (L-NHA), 
      L-arginine, and citrulline. Deformylation of L-NMA and L-NHMA precedes the 
      formation of citrulline and nitric oxide (.NO). Partial uncoupling of NADPH 
      oxidation during L-NMA and L-NHMA processing results in hydrogen peroxide 
      formation. The apparent Km values for L-NMA and L-NHMA are 3.1 and 7.4 microM, 
      respectively. Turnover of L-NMA and L-NHMA to .NO and citrulline is slow relative 
      to L-arginine: Vmax(L-arginine/L-NMA) = 20:1; Vmax(L-arginine)/(L-NHMA) = 13:1. 
      NOS contains a functional cytochrome P-450-type heme, and the formation of these 
      products from L-NMA is consistent with cytochrome P-450 monooxygenase chemistry. 
      Other than the NOS reaction intermediate L-NHA, L-NMA and L-NHMA are the first 
      NG-substituted L-arginines identified as substrates for NOS.
FAU - Olken, N M
AU  - Olken NM
AD  - Interdepartmental Program in Medicinal Chemistry, College of Pharmacy, University 
      of Michigan, Ann Arbor 48109-1065.
FAU - Marletta, M A
AU  - Marletta MA
LA  - eng
GR  - CA 50414/CA/NCI NIH HHS/United States
GR  - T32 GM 07767/GM/NIGMS NIH HHS/United States
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - Biochemistry
JT  - Biochemistry
JID - 0370623
RN  - 1HG84L3525 (Formaldehyde)
RN  - 27JT06E6GR (omega-N-Methylarginine)
RN  - 29VT07BGDA (Citrulline)
RN  - 53-59-8 (NADP)
RN  - 94ZLA3W45F (Arginine)
RN  - BBX060AN9V (Hydrogen Peroxide)
RN  - EC 1.11.1.6 (Catalase)
RN  - EC 1.14.13.39 (Nitric Oxide Synthase)
RN  - EC 1.15.1.1 (Superoxide Dismutase)
RN  - EC 1.4.- (Amino Acid Oxidoreductases)
SB  - IM
MH  - Amino Acid Oxidoreductases/*antagonists & inhibitors/metabolism
MH  - Animals
MH  - Arginine/*analogs & derivatives/chemical 
      synthesis/chemistry/metabolism/pharmacology
MH  - Catalase/pharmacology
MH  - Citrulline/metabolism
MH  - Formaldehyde/metabolism
MH  - Hydrogen Peroxide/metabolism
MH  - In Vitro Techniques
MH  - Macrophages/enzymology
MH  - Mice
MH  - NADP/metabolism
MH  - Nitric Oxide Synthase
MH  - Structure-Activity Relationship
MH  - Superoxide Dismutase/pharmacology
MH  - omega-N-Methylarginine
EDAT- 1993/09/21 00:00
MHDA- 1993/09/21 00:01
CRDT- 1993/09/21 00:00
PHST- 1993/09/21 00:00 [pubmed]
PHST- 1993/09/21 00:01 [medline]
PHST- 1993/09/21 00:00 [entrez]
AID - 10.1021/bi00088a020 [doi]
PST - ppublish
SO  - Biochemistry. 1993 Sep 21;32(37):9677-85. doi: 10.1021/bi00088a020.