Structural stability of adenovirus type 5
Structural stability of adenovirus type 5
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DOI：
10.1002/jps.10340
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发表时间：
2003-03-01
影响因子：
3.8
通讯作者：
Middaugh, CR
中科院分区：
文献类型：
--
作者：
Rexroad, J;Wiethoff, CM;Middaugh, CR
Thermally induced structural changes in adenovirus type 5 (Ad) in the presence of either 2 or 10% sucrose were investigated using a variety of biophysical techniques. In solutions containing 2% sucrose, a highly cooperative transition in the structure of the virus was observed at 45degreesC as detected by tryptophan fluorescence, derivative UV absorption spectroscopy, circular dichroism (CD), and dynamic and static light scattering. This transition resulted in (at least partial) disassembly of the virus and a concomitant increase in the accessibility of the viral DNA to the fluorescent dye, TOTO-1. Capsid disassembly was verified by transmission electron microscopy, which showed ruptured icosahedral vertices near 45degreesC followed by complete capsid disassembly at higher temperatures. SDS-PAGE of thermally treated Ad suggests that the penton base (protein III) and protein IIIa (located in the peripentonal. region) are significantly more labile than other capsid proteins and may be the initial instigators in capsid disassembly. Additional discrete structural transitions were observed in viral proteins using the aforementioned spectroscopic techniques. Thermally induced rearrangements of the condensed DNA at higher temperatures were also detected by the appearance of "psi"-like features in the CD spectra as well as a dramatic decrease in accessibility of DNA to TOTO-1. These transitions corresponded to discrete endothermic events that are also detected by differential scanning calorimetry. By increasing the concentration of sucrose to 10%, secondary and tertiary structural features of adenoviral proteins were significantly stabilized, although loss of quaternary structure at 45degreesC was still observed. (C) 2003 Wiley-Liss, Inc. and the American Pharmaceutical Association J Pharm Sci 92:665-678, 2003.
