Additions and Corrections-Kinetics of Carboxypeptidase Action. I. Effect of Various Extrinsic Factors on Kinetic Parameters

Neutron Crystal Structure of RAS GTPase Puts in Question the Protonation State of the GTP γ-Phosphate

“…The glass electrodes were calibrated for pH measurements in H 2 O such that readings in D 2 O yielded apparent pH values, pH*, that do not correspond directly to the pD. The conversion to pD was worked out in the 1950s as pD ϭ pH* ϩ 0.4 (34), and refined in the early 1960s to pD ϭ pH* ϩ 0.44 (35). A more recent study that included a large number of ionizable compounds of diverse types concluded that the most accurate conversion factor is pD ϭ pH* ϩ 0.45 and stated that the pK a H* values measured from pH* titration using a glass electrode in deuterated medium can be converted into pK a D by the addition of the 0.4 (or 0.45) factor (36).…”

Crystal Structure of Reaction Intermediates in Pyruvate Class II Aldolase

“…Solvent isotope effects were determined using the normal enzyme activity assays except that assay solutions and substrate were dissolved in D 2 O, evaporated to dryness two times, and then redissolved in the appropriate amount of D 2 O. The assay buffer was adjusted to pD 8.0 using NaOD according to the equation pD ϭ pH meter reading ϩ 0.4 (18).…”

Lipid-Protein Interactions in the Regulated Betaine Symporter BetP Probed by Infrared Spectroscopy

“…The final pH value was controlled with a pH meter. The formula pD ϭ pH ϩ 0.4 was used to measure the pD value of the deuterated buffer as the pD values are 0.4 digit higher than the pH meter reading (25,26).…”