Affordable Access

deepdyve-link deepdyve-link
Publisher Website

Application of a sensitive near-field microwave microprobe to the nondestructive characterization of microbial rhodopsin.

Authors
  • 1
  • 1 Department of Physics, Kunsan National University, Gunsan 573-701, Korea. , (North Korea)
Type
Published Article
Journal
Journal of Biophotonics
1864-0648
Publisher
Wiley Blackwell (John Wiley & Sons)
Publication Date
Volume
6
Issue
2
Pages
163–170
Identifiers
DOI: 10.1002/jbio.201100143
PMID: 22517728
Source
Medline
License
Unknown

Abstract

We study the opto-electrical properties of Natronomonas pharaonis sensory rhodopsin II (NpSRII) by using a near-field microwave microprobe (NFMM) under external light illumination. To investigate the possibility of application of NFMM to biological macromolecules, we used time dependent properties of NPSRII before/after light activation which has three distinct states - ground-state, M-state, and O-state. The diagnostic ability of NFMM is demonstrated by measuring the microwave reflection coefficient (S(11)) spectrum of NpSRII under steady-state illumination in the wavelength range of 350-650 nm. Moreover, we present microwave reflection coefficient S(11) spectra in the same wavelength range for two fast-photocycling rhodopsins: green light-absorbing proteorhodopsin (GPR) and Gloeobacter rhodopsin (GR). In addition the frequency sweep shift can be detected completely even for tiny amounts of sample (∼10(-3) OD of rhodopsin). Based on these results NFMM shows both very high sensitivity for detecting conformational changes and produces a good time-resolved spectrum.

Statistics

Seen <100 times