primers utilized in the construction of PfTR mutants were purchased
from Integrated DNA Technologies (Coralville, IA). The Quickchange
site-directed mutagenesis kit was purchased from Agilent Technologies
(Santa Clara, CA). Vent DNA polymerase, NdeI, SapI, T4 DNA ligase, E. coli ER2566 competent cells, and chitin-agarose beads
were purchased from New England Biolabs (Ipswich, MA). GSH-sepharose
4 Fast Flow, benzamidine sepharose, and 2′-4′-ADP-sepharose
resins were obtained from GE Healthcare (Waukesha, WI). Sephacryl
S-200 resin was purchased from Amersham Pharmacia (Uppsala, Sweden).
NADPH was obtained from AppliChem (Darmstadt, Germany). N-(Methyl)mercaptoacetamide, βME, and
were from Sigma-Aldrich (St. Louis, MO). Bovine thrombin was purchased
from BioPharm Laboratories (Bluffdale, UT).
was from Acros Organics (Morris Plains, NJ). Hydrogen peroxide (30%
solution) and EDTA were purchased from Fisher Scientific (Fair Lawn,
NJ). All enzyme kinetic assays were performed on a Cary50 UV–vis
spectrophotometer (Cary, Walnut Creek, CA) and were conducted at
room temperature.