Authors: S.W. Leung and J.C.K. Lai
Affilation: Idaho State University, United States
Pages: 246 - 249
Keywords: surfactant, enzyme, transport, membrane
Differential Effects of Surfactants on Enzyme Activity and Transport across a Semipermeable Cell Solomon Leung1 and James C.K. Lai2 1 Corresponding Author, College of Engineering, P.O. Box 8060, Idaho State University, Pocatello, ID 83209 Fax: 208-282-4538; tel: 208-282-2524; email: firstname.lastname@example.org 2 College of Pharmacy, P.O. Box 8334, Idaho State University, Pocatello, ID 83209 Fax: 208-282-4305; tel: 208-282-2275; email: email@example.com We systematically investigated how anionic surfactants of various hydrophilicities affected the activities of three metabolically important enzymes –– glutamate dehydrogenase (GDH), lactate dehydrogenase (LDH), and malate dehydrogenase (MDH) –– of different molecular masses at a pH range important to body functions (6.5-7.4). We also investigated the time course of the surfactant concentration dependent effects on LDH. To observe how surfactants would affect the cellar protein transport, a separation cell with a semipermeable membrane was used to simulate a passive mass transport phenomenon between cells, with various concentration combinations of enzymes and surfactants. Activity of enzyme protein of larger molecular mass (GDH) in solution showed less variation compared to those with smaller molecular masses (LDH and MDH), with changes in pH, hydrophilicity, and surfactant concentration. For LDH and MDH, relative activities could change more than 35% with 1 ppm difference in surfactant concentrations. LDH activity also showed time dependent decreases with different surfactant concentrations. For the four anionic surfactants used in this study, there seemed to be a pH dependence on how hydrophilicity would affect cellar protein transfer (across the membrane).