Simplified Procedure for Encapsulating Cytochrome c in Silica Aerogel Nanoarchitectures while Retaining Gas-Phase Bioactivity
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- 作者：Amanda S. Harper-Leatherman ; Mariam Iftikhar ; Adela Ndoi ; Steven J. Scappaticci ; George P. Lisi ; Kaitlyn L. Buzard ; Elizabeth M. Garvey
- 刊名：Langmuir
- 出版年：2012
- 出版时间：October 16, 2012
- 年：2012
- 卷：28
- 期：41
- 页码：14756-14765
- 全文大小：385K
- 年卷期：v.28,no.41(October 16, 2012)
- ISSN：1520-5827
文摘
Cytochrome c (cyt. c) has been encapsulated in silica sol鈥揼els and processed to form bioaerogels with gas-phase activity for nitric oxide through a simplified synthetic procedure. Previous reports demonstrated a need to adsorb cyt. c to metal nanoparticles prior to silica sol鈥揼el encapsulation and processing to form aerogels. We report that cyt. c can be encapsulated in aerogels without added nanoparticles and retain structural stability and gas-phase activity for nitric oxide. While the UV鈥搗isible Soret absorbance and nitric oxide response indicate that cyt. c encapsulated with nanoparticles in aerogels remains slightly more stable and functional than cyt. c encapsulated alone, these properties are not very different in the two types of aerogels. From UV鈥搗isible and Soret circular dichroism results, we infer that cyt. c encapsulated alone self-organizes to reduce contact with the silica gel in a way that may bear at least some resemblance to the way cyt. c self-organizes into superstructures of protein within aerogels when nanoparticles are present. Both the buffer concentration and the cyt. c concentration of solutions used to synthesize the bioaerogels affect the structural integrity of the protein encapsulated alone within the dried aerogels. Optimized bioaerogels are formed when cyt. c is encapsulated from 40 mM phosphate buffered solutions, and when the loaded cyt. c concentration in the aerogel is in the range of 5 to 15 渭M. Increased viability of cyt. c in aerogels is also observed when supercritical fluid used to produce aerogels is vented over relatively long times.