Bacteriorhodopsin encapsulated in transparent sol-gel glass: A new biomaterial

Journal Article · Fri Jan 01 00:00:00 EST 1993 · Chemistry of Materials; (United States)

DOI:https://doi.org/10.1021/cm00025a022· OSTI ID:6719278

Wu, S; Ellerby, L M; Cohan, J S; Dunn, B; El-Sayed, M A; Valentine, J S; Zink, J I ^[1]

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1. Univ. of California, Los Angeles (United States)

The photosynthetic membrane protein of bacteriorhodopsin (bR) was encapsulated in an optically transparent and porous silica matrix using a modified sol-gel procedure. The absorption spectra and the kinetics of the photocycle characteristic of the proton pumping function of bR were studied systematically throughout the different stages of the glass formation process. This new biomaterial was characterized by means of its optical absorption, circular dichroism (CD), and Raman spectra; its photocycle kinetics; the characteristic activation parameters of its photocycle; and its deionization and cation regeneration properties. The global trimeric bR structure, the local structure of the retinal chromophore, and the proton pumping function of bR were not affected by the encapsulation process. It was also found that the bR glass formed allowed transport of small ions such as Ca[sup 2+] in to and out of the glass medium, and those ions were found to affect the properties of the protein just as they do in aqueous suspensions. The bR protein was found to bleach if delipidated prior to encapsulation. These observations as well as analysis of the CD spectrum suggest that the bR is encapsulated along with its membrane lipids. These results taken together suggest that this optically transparent system offers a potentialy useful new bR-containing material for optical imaging and optically based ion-sensoring devices as developed and proposed for other bR-based systems. 24 refs., 8 figs., 2 tabs.

• DOE Contract Number: FG03-88ER13828
• OSTI ID: 6719278
• Journal Information: Chemistry of Materials; (United States), Vol. 5:1; ISSN 0897-4756
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
PROTEINS
ENCAPSULATION
ABSORPTION SPECTROSCOPY
CATIONS
KINETICS
LIPIDS
PHOTOCHEMISTRY
PHOTOSYNTHESIS
RAMAN SPECTROSCOPY
SILICON OXIDES
SOLS
CHALCOGENIDES
CHARGED PARTICLES
CHEMICAL REACTIONS
CHEMISTRY
COLLOIDS
DISPERSIONS
IONS
LASER SPECTROSCOPY
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
SILICON COMPOUNDS
SPECTROSCOPY
SYNTHESIS
360601* - Other Materials- Preparation & Manufacture
400500 - Photochemistry