User profiles for James R. Halpert

James Halpert

University of Arizona
Verified email at arizona.edu
Cited by 16812

The genetic determinants of the CYP3A5 polymorphism

…, I Koch, A Zibat, J Brockmöller, JR Halpert… - Pharmacogenetics …, 2001 - journals.lww.com
CYP3A proteins comprise a significant portion of the hepatic cytochrome P450 (CYP) protein
and they metabolize aroud 50% of drugs currently in use. The dissection of the individual …

An open conformation of mammalian cytochrome P450 2B4 at 1.6-Å resolution

…, MA White, CC Chin, JR Halpert… - Proceedings of the …, 2003 - National Acad Sciences
The xenobiotic metabolizing cytochromes P450 (P450s) are among the most versatile
biological catalysts known, but knowledge of the structural basis for their broad substrate …

Identification and functional characterization of eight CYP3A4 protein variants

…, UA Meyer, KK Khan, YA He, JR Halpert… - Pharmacogenetics …, 2001 - journals.lww.com
The genetic component of the inter-individual variability in CYP3A4 activity has been estimated
to be between 60% and 90%, but the underlying genetic factors remain largely unknown. …

[HTML][HTML] Structure of mammalian cytochrome P450 2B4 complexed with 4-(4-chlorophenyl) imidazole at 1.9-Å resolution: insight into the range of P450 conformations …

…, YA He, EF Johnson, CD Stout, JR Halpert - Journal of Biological …, 2004 - ASBMB
A 1.9-Å molecular structure of the microsomal cytochrome P450 2B4 with the specific
inhibitor 4-(4-chlorophenyl)imidazole (CPI) in the active site was determined by x-ray …

Analysis of human cytochrome P450 3A4 cooperativity: construction and characterization of a site-directed mutant that displays hyperbolic steroid hydroxylation …

GR Harlow, JR Halpert - Proceedings of the National …, 1998 - National Acad Sciences
Cytochrome P450 3A4 is generally considered to be the most important human drug-metabolizing
enzyme and is known to catalyze the oxidation of a number of substrates in a …

cDNA cloning and initial characterization of CYP3A43, a novel human cytochrome P450

TL Domanski, C Finta, JR Halpert… - Molecular …, 2001 - ASPET
The RACE amplification technology was used on a novel CYP3A-like exon 1 sequence
detected during the reverse transcriptase/polymerase chain reaction analysis of human CYP3A …

Midazolam oxidation by cytochrome P450 3A4 and active-site mutants: an evaluation of multiple binding sites and of the metabolic pathway that leads to enzyme …

KK Khan, YQ He, TL Domanski, JR Halpert - Molecular pharmacology, 2002 - ASPET
Midazolam (MDZ) oxidation by recombinant CYP3A4 purified fromEscherichia coli and 30
mutants generated at 15 different substrate recognition site positions has been studied to …

Steroid-based facial amphiphiles for stabilization and crystallization of membrane proteins

…, CV Robinson, AB Ward, JR Halpert… - Proceedings of the …, 2013 - National Acad Sciences
Amphiphile selection is a critical step for structural studies of membrane proteins (MPs). We
have developed a family of steroid-based facial amphiphiles (FAs) that are structurally …

[HTML][HTML] Structure of microsomal cytochrome P450 2B4 complexed with the antifungal drug bifonazole: insight into P450 conformational plasticity and membrane …

…, MA White, BK Muralidhara, L Sun, JR Halpert… - Journal of biological …, 2006 - ASBMB
To better understand ligand-induced structural transitions in cytochrome P450 2B4, protein-ligand
interactions were investigated using a bulky inhibitor. Bifonazole, a broad spectrum …

Structures of cytochrome P450 3A4

EE Scott, JR Halpert - Trends in biochemical sciences, 2005 - cell.com
Cytochrome P450 3A4 (CYP3A4) catalyzes the initial step in the clearance of many
pharmaceuticals and foreign chemicals. The structurally diverse nature of CYP3A4 substrates …