KChannelDB: Extraction of mutation data from the literature 2005, KChannelDB.
This data was extracted from Medline abstracts and full texts (when available) in an automated manner.
The table below describes the selected point mutation and provides links to other documents. The sentence(s) where the point mutation H118K was found are listed after the table.
The mutated residues are also indicated in the family sequence alignments and hyperlinked to the corresponding mutation pages.
Point mutation H118K in KAT1_ARATH
- Normalized representative currents recorded from the wild type KAT1 (this channel will be referred to as H118H) , H118K , H118R , H118D , and H118E channels at pH i = 7.2 in response to voltage pulses to -180 mV are shown in Fig. 5 A
- The H118K and H118R channels with a positively charged amino acid at position 118 activated markedly faster than the H118H channel at pH i = 7.2
- However , T A of H118K and H118R , with two very different side chain structures (Richardson and Richardson , 1989(image) ) but the same positive charge , were virtually indistinguishable
- (B) Henderson-Hasselbalch plot of the normalized t 0.5-pH i relations for the H118E and H118K mutants
- For H118K and H118E , the t 0.5max and t 0.5min values of wild type KAT1 were used because it was difficult to determine the extreme values for these mutant channels
- Within the pH i range of 5.2 to 8.2 , where H118H is very pH i sensitive (see Fig. 2 ) , neither H118E nor H118K showed any marked pH i dependence
- Activation time course of H118E remained slow and mostly independent of pH i and that of H118K remained fast and also independent of pH i in this pH range (Fig. 5 B)
- At the extreme pH i values , however , both H118E and H118K exhibited some pH i dependence
- For example , H118E T A was noticeably and consistently faster at pH i = 4.2 than that at pH i = 5.2 , and H118K T A was slower at pH i = 10.2 than at 8.2 (Fig. 5 B)
- Because t 0.5min for H118E and t 0.5max for H118K could not be obtained , the pH i dependence data were not confidently fitted with the Henderson-Hasselbalch formulation
- However , using pK values of 4.3 and 10.8 , which are often described for the side chains of E and K (Edsall and Wyman , 1958(image) ) , the small pH i dependence of H118E and H118K could be approximated (Fig. 5 B)
- It is also possible that structural determinants other than the amino acid at position 118 are involved in regulating the small pH i sensitivities of the H118E and H118K mutant channels
- Normalized representative tail currents of H118K , H118D , and H118N recorded at +60 mV are compared in Fig. 8 A , and they were indistinguishable
- (A) Representative tail currents from H118N , H118D , and H118K
- (C) Comparison of the p o(V) relations for H118H , H118D , and H118K
- Single-channel current amplitudes are not affected by the H118 mutations Although the first latencies are affected by the charged H118 mutations , the single-channel amplitudes of the H118 mutants (H118D , H118E , H118K , and H118R) were very similar to that of the wild type KAT1 channel
- We also found that the accelerated activation time course in the H118K channel could also be simulated by increasing the value of k 01(0) by ~190% without a change in its voltage dependence (n = 3 , data not shown)
F.Horn (kchanneldbcmbi.ru.nl), 17-Aug-2005