title: Adenosine deaminase-like protein 1 (ADAL1): characterization and substrate specificity in the hydrolysis of N(6)- or O(6)-substituted purine or 2-aminopurine nucleoside monophosphates.
abstract: Human N(6)-methyl-AMP/dAMP aminohydrolase has been shown to be involved in metabolism of pharmacologically important N(6)-substituted purine nucleosides and 5'-monophosphate prodrugs thereof. This enzyme was cloned and expressed in E. coli, and mass spectroscopic analysis followed by amino acid sequence analyses indicated that the protein was adenosine deaminase-like protein isoform 1 (ADAL1). An extensive structure-activity relationship study showed that ADAL1 was able to catalyze removal of different alkyl groups not only from N(6)-substituted purine or 2-aminopurine nucleoside monophosphates but also from O(6)-substituted compounds. The ADAL1 activity was susceptible to modifications in the phosphate moiety but not to changes in the sugar moiety. Overall, our data indicated that ADAL1 specifically acts at the 6-position of purine and 2-aminopurine nucleoside monophosphates. Our results may help designing of new therapeutic nucleoside/nucleotide prodrugs with desired metabolic profiles. Furthermore, amino acid sequence analysis in conjunction with crystallographic data and metal analysis suggested that ADAL1 contains a catalytic zinc ion. Finally, a potential physiological role of ADAL1 is discussed.
authors.affiliation: Pharmasset, Inc., 303A College Road East, Princeton, New Jersey 08540, USA. emurakami@pharmasset.com
authors.forename: Eisuke
authors.initials: E
authors.lastname: Murakami
authors.forename: Haiying
authors.initials: H
authors.lastname: Bao
authors.forename: Ralph T
authors.initials: RT
authors.lastname: Mosley
authors.forename: Jinfa
authors.initials: J
authors.lastname: Du
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Sofia
authors.forename: Phillip A
authors.initials: PA
authors.lastname: Furman
mesh_terms: D015075:2-Aminopurine / Q000737:chemistry / Q000378:metabolism*; D000249:Adenosine Monophosphate / Q000737:chemistry / Q000378:metabolism*; D000595:Amino Acid Sequence; D000619:Aminohydrolases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D055162:Biocatalysis; D045744:Cell Line, Tumor; D003001:Cloning, Molecular; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D006868:Hydrolysis; D007527:Isoenzymes / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D007700:Kinetics; D008969:Molecular Sequence Data; D015394:Molecular Structure; D008970:Molecular Weight; D009700:Nucleoside Deaminases / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D011687:Purines / Q000737:chemistry / Q000378:metabolism*; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D020539:Sequence Analysis, Protein; D017386:Sequence Homology, Amino Acid; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013379:Substrate Specificity; D015032:Zinc / Q000737:chemistry / Q000378:metabolism
chemical_list: D015075:2-Aminopurine; D000249:Adenosine Monophosphate; D000619:Aminohydrolases; D007527:Isoenzymes; D009700:Nucleoside Deaminases; D011687:Purines; D011994:Recombinant Proteins; D015032:Zinc; C568464:MAPDA protein, human