title: Nitric oxide - an activating factor of adenosine deaminase 2 in vitro.
abstract: In this study we have investigated the effect of reactive oxygen species produced by some chemicals in aqueous solutions on activity of adenosine deaminase 2 (ADA2) purified from human blood plasma. An activating effect on ADA2 was observed in vitro with sodium nitroprusside (SNP), the source of NO (nitrosonium ions NO(-) in aqueous solutions). Not SH-groups of cysteine but other amino acid residues sensitive to NO were responsible for ADA2 activation. The SNP-derived activation was more pronounced when purified ADA2 was preincubated with heparin and different proteins as an experimental model of the protein environment in vivo. The most effective was heparin, which is known for its ability to regulate enzyme and protein functions in extracellular matrix. We conclude that ADA2 is a protein with flexible conformation that is affected by the protein environment, and it changes its activity under oxidative (nitrosative) stress.
authors.affiliation: Bunyatyan Institute of Biochemistry, National Academy of Sciences of the Republic of Armenia, Yerevan, Republic of Armenia. biochem@ipia.sci.am
authors.forename: Ye G
authors.initials: YG
authors.lastname: Sargisova
authors.forename: N A
authors.initials: NA
authors.lastname: Andreasyan
authors.forename: H L
authors.initials: HL
authors.lastname: Hayrapetyan
authors.forename: H A
authors.initials: HA
authors.lastname: Harutyunyan
mesh_terms: D000243:Adenosine Deaminase / Q000737:chemistry / Q000378:metabolism*; D004789:Enzyme Activation / Q000187:drug effects; D020536:Enzyme Activators / Q000737:chemistry / Q000494:pharmacology; D005109:Extracellular Matrix / Q000378:metabolism; D006493:Heparin / Q000378:metabolism; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000737:chemistry / Q000378:metabolism*; D007700:Kinetics; D009569:Nitric Oxide / Q000378:metabolism*; D009599:Nitroprusside / Q000737:chemistry / Q000494:pharmacology; D010084:Oxidation-Reduction; D017434:Protein Structure, Tertiary
chemical_list: D020536:Enzyme Activators; D036341:Intercellular Signaling Peptides and Proteins; D009599:Nitroprusside; D009569:Nitric Oxide; D006493:Heparin; C408373:ADA2 protein, human; D000243:Adenosine Deaminase