experiments and computational studies revealed the crucial role of water additive, which assists the proton-coupled electron transfer event for highly acidic amide precursors, followed by an energetically favorable intramolecular CN coupling, causing exclusive fabrication of the C-3 unsu...
cAMP-elevating agents, such as forskolin, can not only induce cancer cell death, but also directly inhibit cell proliferation in some cancer types. In this review, we summarize current understanding of cAMP signaling in cancer biology and immunology and discuss the basis for its context...
onamide 和 N,N .bis( o.nitropheny1) malonamide 在甲 醇 中的 pK 值 的测 定 ,结果 如表 1。 表1 丙二 酰胺 衍生物的 pK 值 Tab .1 p K 。v al ues of tie ma lonamide der ivatives pK i 2 .01 是 N,N .bis ( o—aminopheny1) re al· onamide 中羰 基质 子化 ...
Protein samples at concentrations of ∼1.2 mM were prepared by solvent exchange in D2O containing 100 mM KCl. Amide hydrogen atoms were exchanged by increasing the temperature to the midpoint temperature for 15 min followed by centrifugation. A total volume of at least 1.2 ml was prepared at ...
In the SOFAST spectra a number of cross-peaks migrate as a function of pH, most notably the peak from the backbone amide of Gln2, and the coordinates of this peak were also analysed. The peak positions for the ubiquitin titrations were fitted using non-linear regression to the Henderson–...
tures depend on the precision of proton concentration determination . In this media the proton activity can be measured by using a g ass e ectrode with an a ueous pH sca e . The measured pH(pH m )is changed to proton concentration us- ...
A thermodynamic cycle to calculate p K a values (Minus log of acid dissociation constants) of hydroxamic acids is presented. Hydroxamic acids exist mainly as amide isomers in the aqueous medium. The amide form of hydroxamic acids has two deprotonation sites and may yield either an N-ion or ...
Examines the behavior of hydrogen-ion concentration titration in the carboxyl groups of the N-terminal domain of rat CD2 (CD2d1). Use of amide nitrogen-15, proton nuclear magnetic resonance and carboxyl carbon-13 signals; Presence of glutamate on the binding surface of rat CD2; Characterization ...
In general, the solutions of the drugs were measured by 1H NMR at different pH values of the solvent, and a classical titration curve was obtained by the chemical shift vs. the pH value. All pyridine-containing drugs in our experiments had at least one aromatic proton that could be easily...