The catalytic activities of monomeric enzymes show complex pressure dependence

FEBS Letters

Jaenicke, Rainer¹  Auerbach, Günter¹  Groβ, Michael¹ 

[1] Institut für Biophysik und physikalische Biochemie, Universität Regensburg, Postfach, 8400 Regensburg, Germany

关键词: Activation volume;    Compressibility;    Hen egg-white lysozyme;    Octopine dehydrogenase;    Thermolysin;    Trypsin;    BAPA;    α-N-benzoyl-l-arginino-p-nitroanilid;    FA-Gly-Leu-NH2;    N-(3-[2-furyl-]acryloyl-)glycyl-leucyl-amide;    NAD;    nicotinamide adenine dinucleotide;    NADH. nicotinamide adenine dinucleotide;    reduced;    ODH;    octopine dehydrogenase;    ΔV≠;    activation volume;   

DOI  :  10.1016/0014-5793(93)80120-J

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

High hydrostatic pressures in the biologically relevant range (⩽ 1,200 bar) are known to cause dissociation of oligomeric enzymes in vitro, whereas protein denaturation requires pressures far beyond this range. Pressure-induced inactivation phenomena attributable to neither of these effects are shown to occur in monomeric enzymes. Three different types of pressure dependence can be distinguished: (1) a linear dependence of catalytic rate constants on pressure, as predicted by the activated complex theory, observed for lysozyme and thermolysin; (2) a biphasic profile consisting of two linear contributions, found for trypsin; (3) maximum curves, as observed for both directions of the octopine dehydrogenase reaction. The third case may be ascribed to a pressure-induced decrease in the partial specific volume of the protein, resulting in reduced flexibility of the active site. This mechanism may also apply to the pressure-induced inactivation of assembly systems stabilized against dissociation in the cell.

【 授权许可】

Unknown