Abstract:
:In vitro and in situ tests have been run to characterize the reaction of the mettalochromic indicator, arsenazo III, with calcium. Job plots as well as plots of indicator absorbance vs. [Ca2+] at different indicator concentrations show a 1:1 reaction stoichiometry. Equilibrium analysis and analysis using Adair's equation are also consistent with 1:1 complexes being formed and give estimates of 34 and 45 muM for the apparent dissociation constant. In situ tests were carried out using giant neurons from Archidoris monteryensis, a marine gastropod mollusc. Dye absorbance changes were measured during voltage clamp pulses which produced a fixed calcium influx. The dependence of absorbance change on total dye concentration is consistent with the formation of a 1:1 complex of Ca with ArIII if measurements are made during the initial period of the loading pulse, less than 300 ms, although the apparent dependency changes with longer delay in measurements from the onset of the pulse.
journal_name
Biophys Jjournal_title
Biophysical journalauthors
Ahmed Z,Kragie L,Connor JAdoi
10.1016/S0006-3495(80)85025-9subject
Has Abstractpub_date
1980-12-01 00:00:00pages
907-20issue
3eissn
0006-3495issn
1542-0086pii
S0006-3495(80)85025-9journal_volume
32pub_type
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journal_title:Biophysical journal
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journal_title:Biophysical journal
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pub_type: 杂志文章
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更新日期:1980-08-01 00:00:00
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pub_type: 杂志文章
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更新日期:1984-10-01 00:00:00
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pub_type: 杂志文章
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更新日期:1998-02-01 00:00:00
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journal_title:Biophysical journal
pub_type: 杂志文章
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更新日期:1996-12-01 00:00:00
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journal_title:Biophysical journal
pub_type: 杂志文章
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更新日期:1981-07-01 00:00:00