Influence of Growth Temperature on Structure, Thermostability and Kinetic Properties of the ATPase Coupling Factor AF1 of a Thermophilic Blue‐Green Alga (Cyanobacterium)

• DOI: 10.1111/j.1432-1033.1981.tb06419.x
• Publication Date: 2010-07-21T14:52:52Z
• Authors: Markus WOLF; Andres BINDER; Reinhard BACHOFEN
• Keywords: Thermostability

The coupling factor AF 1 isolated from cells of the thermophilic blue‐green alga Mastigocladus laminosus grown at 40°C, 50°C and 60°C is investigated compared with chloroplast CF . It demonstrated that structure affected by growth temperature. shows a split α‐band in dodecylsulfate/polyacrylamide gel electrophoresis which not observed 40°C or 50°C. Only aggregates allophycocyanin. stable up to 85°C for 60 min whereas denture between 65°C 70°C. much less stable. In contrast structure, kinetic properties are influenced Furthermore, reaction rates all three preparations have same temperature optimum also identical were determined more detail. absence ADP saturation curve ATP Michaelis‐Menten kinetics K m = 480 μM V 30 μmol hydrolyzed × mg protein −1 With addition this becomes sigmoidal decreases. This behaviour Hill values suggest an allosteric enzyme two active sites acting cooperatively. as product ATPase inhibits enzyme. inhibition simply competitive, it influences cooperativity sites.