Catalytic properties and conformation of hydrophobized α‐chymotrypsin incorporated into a bilayer lipid membrane

FEBS Letters

Kozlova, N.O¹  Bruskovskaya, I.B¹  Melik-Nubarov, N.S¹  Yaroslavov, A.A¹  Kabanov, V.A¹ 

[1] Department of Polymer Science, School of Chemistry, Moscow State University, Leninskiye Gory, Moscow 119899, Russian Federation

关键词: α-Chymotrypsin;    Catalytic activity;    Conformation;    Hydrophobization;    Protein-lipid interaction;    ATEE;    N-acetyl-L-tyrosine ethyl ester;    NHSS;    stearic acid N-hydroxysuccinimide ester;    PC;    egg yolk phosphatidylcholine;    STI;    soybean trypsin inhibitor;   

DOI  :  10.1016/S0014-5793(99)01449-0

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

A set of artificially hydrophobized α-chymotrypsin derivatives, carrying 2–11 stearoyl residues per enzyme molecule, were synthesized and their catalytic parameters and conformation in water solution and in the liposome-bound state were investigated. Hydrophobization of α-chymotrypsin and its further incorporation into phosphatidylcholine (PC) liposomes have no effect on the rate constant of the N-acetyl-L-tyrosine ethyl ester (ATEE) ester bond hydrolysis (k _cat). At the same time, an increase in the number of stearoyl residues attached to the enzyme results in a drastic decrease of ATEE binding to the active center (K _M increase). Incorporation of the hydrophobized enzyme into the PC liposome membrane results in K _M recovery to nearly that of native α-chymotrypsin. The above changes are accompanied by partial unfolding of the enzyme molecules observed by fluorescence measurements. The obtained results are of interest to mimic the contribution of surface hydrophobic sites in the functioning of membrane proteins.

【 授权许可】

Unknown