ISSN:
0006-3525
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The time decay of fluorescence anisotropy for a dansylaziridine (DANZ) conjugate with Met-25, which lies within the N-terminal lobe of troponin C (TnC), shows at 10 and 25°C a longer correlation time characteristic of the entire molecule and a shorter correlation time arising from a more localized motion of the probe. In the absence of Ca2+, the amplitude of the shorter correlation time increases, suggesting an increased mobility of the probe. At 40°C, in both the absence and presence of Ca2+, a significant increase in probe mobility occurs. A 2,6-toluidinyl naphthalene sulfonate (2,6-TNS) complex with Ca2+-liganded TnC shows only the longer correlation time at 12 and 25°C. An N-(iodoacetylaminoethyl-5-naphthylamine-1-sulfonate) conjugate with Cys-98 shows both a long and a short correlation time; the amplitude of the shorter correlation time is greater than for the DANZ conjugate. At 9, 25, and 40°C in the presence of Ca2+, and at 9°C in its absence, the magnitude of the long correlation time is consistent with motion of the entire molecule; at higher temperatures in the absence of Ca2+ it is substantially smaller, suggesting the presence of internal rotation. For Ca2+-liganded TnC at temperatures of 25°C or lower, the results with all three labels are interpretable in terms of the crystallographic structure of TnC.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/bip.360260713
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