Thermal Tolerance of Archael Membrane-Bound Enzymes.
Abstract
The molecular mechanisms for thermal tolerance of proteins and other components from hyperthermophilic microorganisms (organisms that grow above 100 deg C) have yet to be determined. The objective of this work was to identify an approach to understand the role of hydrophobic membrane components (i.e., lipids) in conferring thermal tolerance to a heat-stable membrane-bound enzyme. A tightly-membrane-associated enzyme (hydrogenase) that is a key component of the energy metabolism of the hyperthermophile Pyrodictium abyssi (grows at up to 110 deg C), can be assayed at temperatures up to 120 deg C. The specific aims for this project period were to reconstitute partially purified P. abyssi hydrogenase into proteoliposomes to enable assessment of the roles of lipids in conferring stability. This objective was partially achieved, although the amount of enzyme incorporation into liposomes was low, and enzyme activity loss was rapid. The P. abyssi detergent-solubilized enzyme was characterized for some biochemical and physiological properties especially for its function as a membrane-bound respiratory-type uptake hydrogenase enzyme. Another membrane-bound enzyme, sulfur reductase, was partially purified and characterized, and a S(exp 0)-reducing electron transport chain was partially identified.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 30, 1998
- Accession Number
- ADA358148
Entities
People
- Robert J. Maier
Organizations
- Johns Hopkins University