Carboxy-SNARF-1 - intracellular quenching - intracellular pH - pKaCarboxy-SNARF-1 is an emission-changing, pH-sensitive probe for measurements of intracellular pH. However, the protonated and deprotonated forms of the dye interact differently with intracellular constituents, and this imposes new ...
pKa and pH - The fundamental distinction between pKa and pH is that pKa denotes an acid's dissociation, whereas pH denotes a system's acidity or alkalinity.
The pKa value thus describes the pH-dependence of the rcrg=[A−]/[HA] ratio for a given titratable group. In addition to being pH-dependent, rcrg depends on the free energy difference between the protonated (HA) and deprotonated (A−) forms of the titrable group in question. In the...
The NLS-directed nuclear accumulation of the c-Met fragment is pH-dependent Because the imidazole group of histidine has a pKa of 6.0–6.2, which is fairly close to physiological pH, it can be protonated or deprotonated depending on the pH inside the cell.38–40 Thus, under physiological ...
insulated cavity; however, even though N149 and Q204 face away from the chromophore we cannot rule out the possibility that the environment of the chromophore is altered by mutation of these residues resulting in a structure which can no longer switch between the protonated and deprotonated forms...
The detection of protonated and deprotonated species is possible by controlling the pH of the medium and monitoring the optical changes in the spectral pattern as a function of this parameter, in order to obtain a calibration curve [2]. For a fluorescent pH probe to be effectively applicable ...
Absorption and fluorescence spectra of the protonated and deprotonated forms of ACMA (A1324) are quite similar. This observation, and the listed pKa value, are reported in published references. Accumulation of the probe in the presence of transmembrane pH gradients results in fluo...
Almost all known pH-responsive antibodies sense pH due to histidine residues within their variable regions. pKa value of the histidine side chain is about 6; thus, at pH below 6.0, the histidine side chain is mostly protonated, whereas, at physiologic pH 7.4, it is deprotonated. It was show...
(see later discussion). As pH is increased to 4, Asp163 becomes completely deprotonated (charged) and Asp164 remains protonated (neutral); the radius of gyration increases to about 5 Å. Interestingly, the hydration number of Asp164 increases to 2, whereas that of Asp163 remains below 1...
(H2) is the only residue with a pKain this range of pH, we explored its protonation state. As shown by the corresponding attenuated total reflectance Fourier-transformed infrared spectroscopy (ATR-FTIR) spectra (Fig. 1j), H2is protonated as a positively charged imidazolium group in the low-...