Activating the phosphate nucleophile at the catalytic site of purine nucleoside phosphorylase: a vibrational spectroscopic study.
Difference Raman and FTIR studies complemented by vibrational analysis based on ab initio calculations show that the dianionic phosphate in the PNP.ImmH.PO4 complex is forced into a unique bonding arrangement in which one of the PO bonds is greatly polarized by enzyme active site interactions, such that it resembles a PO bond that is about one-quarter of the way toward forming a bridging P-O-C single P-O bond.
Deng
Hua
H
Department of Biochemistry, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 10461, USA. hdeng@aecom.yu.edu
Lewandowicz
Andrzej
A
Schramm
Vern L
VL
Callender
Robert
R
D000818:Animals; D001665:Binding Sites; D002384:Catalysis; D002417:Cattle; D006801:Humans; D006860:Hydrogen Bonding; D007700:Kinetics; D010755:Organophosphates / Q000737:chemistry* / Q000378:metabolism; D011684:Purine Nucleosides; D011683:Purine-Nucleoside Phosphorylase / Q000737:chemistry* / Q000378:metabolism; D011744:Pyrimidinones / Q000737:chemistry / Q000378:metabolism; D011758:Pyrroles / Q000737:chemistry / Q000378:metabolism; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman; D013816:Thermodynamics
D010755:Organophosphates; D011684:Purine Nucleosides; D011744:Pyrimidinones; D011758:Pyrroles; C113101:forodesine; D011683:Purine-Nucleoside Phosphorylase