Regulation of the catalytic activity and oligomeric composition of enzymes in reversed micelles of surfactants in organic solvents

FEBS Letters

Kabanov, Alexander V.¹  Klyachko, Nataliya L.¹  Levashov, Andrey V.¹  Nametkin, Sergey N.¹ 

[1] Department of Chemical Enzymology, Moscow State University, Moscow, USSR

关键词: Alkaline phosphatase;    Aerosol OT;    α-Chymotrypsin;    Reversed micelle;    Micellar enzymology;    AOT;    Aerosole OT (sodium bis(2-ethylhexyl)sulfosuccinate);    AP;    alkaline phosphatase;    CT;    α-chymotrypsin;    CBZTNP;    N-benzloxycarbonyl-L-tyrosine p-nitrophenylphosphate;    SPDP;    succimidyl-3-(2-pyridylthio)propionate;   

DOI  :  10.1016/0014-5793(91)80103-A

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The Phenomenon of the regulation of the catalytic activity of enzymes via changing their oligomeric composition in the system of reversed micelles of sodium bis(2-ethylhexy)sulfosuccinate (AOT) in octane was studied using z-chymotrypsin (CT) from bovine brain and alkaline phosphatase (AP) from calf intestinal mucosa. The dependences of the enzyme catalytic activity on the AOT hydration degree (W=[H₂O][AOT]), the parameter determining the radius (r ₄) of the inner cavity of micelles, usually represent the bell-shaped curves. The maximal catalytic activity is observed at such W_o when r ₄ is equal to the size of the enzyme molecule. The position of this maximum strictly correlates with the enzyme oligomeric composition. Thus, in the case of CT this is observed at W_o =12 when r ₁ is equal to the radius (r_p ) of the CT globule. In the case of artificially produced conjugate containing six cross-linked CT molecules, this is observed at W _o=43 when r ₄ is equal to the radius of the sphere surrounding the absolute octahedron composed of six CT globules. The dependence of the catalytic activity of AP on Wo represent a curve with two maxima that are observed when r ₄ is equal to r _p of either AP monomer (W=17) or AP dimer (W _o=25), Ultracentrifugation experiments revealed that variation of W _o causes a change in the oligomeric composition of AP its transition from monomeric (W _o<20) to demeric form (W _o > 20). Hence, the observed maxima correspond to functioning of different oligomeric forms of AP.

【 授权许可】

Unknown