Temperature dependent UV-Vis spectral changes in hydrogen-and deuterium-bonded photosynthetic reaction centers of Rhodobacter sphaeroides

The UV-Vis absorption spectra of detergent-isolated hydrogen-and deuterium-bonded reaction centers (RCs) from Rhodobacter sphaeroides PUC 705Ba were examined as a function of temperature between 20 and 55 degree C. The enthalpy and entropy of denaturation for the specimens was determined, revealing...

Full description

Saved in:
Bibliographic Details
Published in:Photosynthetica 2006-09, Vol.44 (3), p.433-438
Main Authors: Ostafin, A. E., Popova, J. A., Payne, C. K., Mizukami, H., Norris, J. R.
Format: Article
Language:English
Subjects:
Rhodobacter sphaeroides
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The UV-Vis absorption spectra of detergent-isolated hydrogen-and deuterium-bonded reaction centers (RCs) from Rhodobacter sphaeroides PUC 705Ba were examined as a function of temperature between 20 and 55 degree C. The enthalpy and entropy of denaturation for the specimens was determined, revealing that their process of thermal denaturation is significantly different. Deuterium-bonded RCs are most stable at 37 degree C, rather than at room temperature, and undergo a 'cold denaturation' as the temperature is lowered to room temperature. At room temperature the addition of 1,3,5-heptanetriol brought the deuterium-bonded RC back to its more stable configuration. Hence the hydrogen bonding interactions in the RC do influence its conformation and this is reflected in the microenvironment of its associated pigments.
ISSN:0300-3604
1573-9058
DOI:10.1007/s11099-006-0047-0