Kropacheva Tatyana N, Raap Jan
Chemistry Department, Udmurt State University, Izhevsk, Russia.
Chem Biodivers. 2007 Jun;4(6):1388-94. doi: 10.1002/cbdv.200790118.
Catalytic reactions performed with enzymes localized in lipid vesicles or in whole cells represent a new, promising approach in biocatalysis. The delivery of different substrates into these micro- or nano-'reactors' requires a sufficient permeability of lipid membranes. To increase the permeability of lipid bilayers, one may use different membrane-active peptides, including peptaibols. In the present study, the trypsin-catalyzed hydrolysis of N(alpha)-benzoyl-L-arginine-para-nitroanilide (BAPA; 1) was studied in a phospholipid vesicular system made of phosphatidylcholine (POC), in the presence of the peptaibols alamethicin (ALM) or zervamicin IIB (ZER). Two different manners of compartmentalization of substrate and enzyme (enzyme- vs. substrate-containing vesicles) were used. The kinetics parameters of the reaction in homogeneous solution and in the vesicular systems were determined. The rate of the extra- or intravesicular enzymatic reaction was found to be controlled by substrate diffusion through the lipid bilayer. In comparison with untreated vesicular systems, an up to seven-fold increase in reaction rate was observed in the presence of either ALM or ZER.
在脂质囊泡或全细胞中进行的酶催化反应代表了生物催化中一种新的、有前景的方法。将不同底物输送到这些微反应器或纳米反应器中需要脂质膜具有足够的通透性。为了增加脂质双层的通透性，可以使用不同的膜活性肽，包括短杆菌肽。在本研究中，在由磷脂酰胆碱（POC）制成的磷脂囊泡系统中，在短杆菌肽A（ALM）或泽尔瓦霉素IIB（ZER）存在的情况下，研究了胰蛋白酶催化的N（α）-苯甲酰-L-精氨酸对硝基苯胺（BAPA；1）的水解反应。使用了两种不同的底物和酶分隔方式（含酶囊泡与含底物囊泡）。测定了均相溶液和囊泡系统中反应的动力学参数。发现囊泡外或囊泡内酶促反应的速率受底物通过脂质双层扩散的控制。与未处理的囊泡系统相比，在存在ALM或ZER的情况下，反应速率提高了多达7倍。
