title: ADA2 isoform of adenosine deaminase from pleural fluid.
abstract: Adenosine deaminase isoenzyme 2 (ADA2) was isolated from human pleural fluid for the first time. Molecular and kinetic properties were characterized. It was shown that the inhibitors of adenosine deaminase isoenzyme 1 (ADA1), adenosine, and erithro-9-(2-hydroxy-3-nonyl)adenine (EHNA) derivatives are poor inhibitors of ADA2. Comparison of the interaction of ADA2 and ADA1 with adenosine and its derivative, 1-deazaadenosine, indicates that the isoenzymes have similar active centers. The absence of ADA2 inhibition by EHNA is evidence of a difference of these active centers in a close environment. The possible role of Zn2+ ions and the participation of acidic amino acids Glu and Asp in adenosine deamination catalyzed by ADA2 were shown.
authors.affiliation: H. Buniatian Institute of Biochemistry, Armenia NAS, 5/1 Sevak Str, Yerevan 375014, Republic of Armenia.
authors.forename: Nune A
authors.initials: NA
authors.lastname: Andreasyan
authors.forename: Hripsime L
authors.initials: HL
authors.lastname: Hairapetyan
authors.forename: Yelizaveta G
authors.initials: YG
authors.lastname: Sargisova
authors.forename: Sona S
authors.initials: SS
authors.lastname: Mardanyan
mesh_terms: D000243:Adenosine Deaminase / Q000302:isolation & purification / Q000378:metabolism*; D058892:Adenosine Deaminase Inhibitors; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007527:Isoenzymes / Q000037:antagonists & inhibitors / Q000302:isolation & purification / Q000378:metabolism*; D007700:Kinetics; D008970:Molecular Weight; D010994:Pleura / Q000201:enzymology*
chemical_list: D058892:Adenosine Deaminase Inhibitors; D004791:Enzyme Inhibitors; D007527:Isoenzymes; D000243:Adenosine Deaminase