TY - JOUR
T1 - A novel nucleoside prodrug-activating enzyme
T2 - substrate specificity of biphenyl hydrolase-like protein.
AU - Kim, Insook
AU - Song, Xueqin
AU - Vig, Balvinder S.
AU - Mittal, Sachin
AU - Shin, Ho Chul
AU - Lorenzi, Philip J.
AU - Amidon, Gordon L.
PY - 2004
Y1 - 2004
N2 - Biphenyl hydrolase-like protein (BPHL, NCBI accession number NP_004323) is a novel human serine hydrolase recently identified as a human valacyclovirase, catalyzing the hydrolytic activation of the antiviral prodrugs valacyclovir and valganciclovir. The substrate specificity of BPHL was investigated with a series of amino acid ester prodrugs of the therapeutic nucleoside analogues: acyclovir, zidovudine, floxuridine, 2-bromo-5,6-dichloro-1-(beta-D-ribofuranosyl) benzimidazole, and gemcitabine. The hydrolysis of typical esterase and aminopeptidase substrates by BPHL was also investigated. The results indicate that the substrate specificity of BPHL is largely determined by the amino acid acyl promoiety, and is less sensitive to the nucleoside parent drugs. For all nucleoside parent drugs, BPHL preferred the hydrophobic amino acids valine, phenylalanine, and proline over the charged amino acids lysine and aspartic acid. The position and monoester or diester form of the prodrug were also important, with BPHL exhibiting higher affinity for the 5'-esters than for the 3'-esters and the 3',5'-diesters irrespective of amino acid type. Further, the presence of the 3'-amino acid ester considerably reduced the hydrolysis rate of the 5'-amino acid ester functionality. BPHL exhibited stereoselectivity with an L/D specificity ratio of 32 for 5'-valyl floxuridine and 1.5 for 5'-phenylalanyl floxuridine. The substrate specificity suggests that the substrate-binding pocket of BPHL has a hydrophobic acyl binding site which can accommodate the positively charged alpha-amino group, while having an alcohol leaving group binding site that can accommodate nucleoside analogues with a relatively generous spatial allowance. In conclusion, BPHL catalyzes the hydrolytic activation of amino acid esters of a broad range of therapeutic nucleoside analogues in addition to valacyclovir and valganciclovir and has considerable potential for utilization as an activation target for design of antiviral and anticancer nucleoside analogue prodrugs.
AB - Biphenyl hydrolase-like protein (BPHL, NCBI accession number NP_004323) is a novel human serine hydrolase recently identified as a human valacyclovirase, catalyzing the hydrolytic activation of the antiviral prodrugs valacyclovir and valganciclovir. The substrate specificity of BPHL was investigated with a series of amino acid ester prodrugs of the therapeutic nucleoside analogues: acyclovir, zidovudine, floxuridine, 2-bromo-5,6-dichloro-1-(beta-D-ribofuranosyl) benzimidazole, and gemcitabine. The hydrolysis of typical esterase and aminopeptidase substrates by BPHL was also investigated. The results indicate that the substrate specificity of BPHL is largely determined by the amino acid acyl promoiety, and is less sensitive to the nucleoside parent drugs. For all nucleoside parent drugs, BPHL preferred the hydrophobic amino acids valine, phenylalanine, and proline over the charged amino acids lysine and aspartic acid. The position and monoester or diester form of the prodrug were also important, with BPHL exhibiting higher affinity for the 5'-esters than for the 3'-esters and the 3',5'-diesters irrespective of amino acid type. Further, the presence of the 3'-amino acid ester considerably reduced the hydrolysis rate of the 5'-amino acid ester functionality. BPHL exhibited stereoselectivity with an L/D specificity ratio of 32 for 5'-valyl floxuridine and 1.5 for 5'-phenylalanyl floxuridine. The substrate specificity suggests that the substrate-binding pocket of BPHL has a hydrophobic acyl binding site which can accommodate the positively charged alpha-amino group, while having an alcohol leaving group binding site that can accommodate nucleoside analogues with a relatively generous spatial allowance. In conclusion, BPHL catalyzes the hydrolytic activation of amino acid esters of a broad range of therapeutic nucleoside analogues in addition to valacyclovir and valganciclovir and has considerable potential for utilization as an activation target for design of antiviral and anticancer nucleoside analogue prodrugs.
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U2 - 10.1021/mp0499757
DO - 10.1021/mp0499757
M3 - Article
C2 - 15832508
AN - SCOPUS:18044367552
SN - 1543-8384
VL - 1
SP - 117
EP - 127
JO - Molecular Pharmaceutics
JF - Molecular Pharmaceutics
IS - 2
ER -