Pedrosa M M, Legaz M E
Laboratorio de Fisiologia Vegetal, Facultad de Biologia, Universidad Complutense, Madrid, Spain.
Electrophoresis. 1995 Apr;16(4):659-69. doi: 10.1002/elps.11501601106.
Four major arginase isoforms, I, II, III and IV, have been detected in Evernia prunastri thallus. They differ in terms of both physical and biochemical properties. The isoelectric point (pI) of these proteins has been determined by both isoelectric focusing in density gradient column and high-performance capillary electrophoresis (HPCE). Isoelectric focusing revealed charge microheterogeneity for isoforms II and IV whereas arginases I and II had the same pI value of 5.8. HPCE separation confirmed this charge microheterogeneity for isoform IV but not for isoform III, and provided evidence of microheterogeneity for isoforms I and II. The effect of various electrolyte buffers and running conditions on the HPCE separation of arginase isoform were investigated. Addition of 0.5 mM spermidine (SPD) to the running buffer reduced the electroosmotic flow (EOF) and permitted discriminating between the native proteins and protein fragments.
在扁枝衣叶状体中检测到四种主要的精氨酸酶同工型，即I、II、III和IV。它们在物理和生化特性方面存在差异。这些蛋白质的等电点（pI）已通过密度梯度柱中的等电聚焦和高效毛细管电泳（HPCE）来测定。等电聚焦显示同工型II和IV存在电荷微不均一性，而精氨酸酶I和II的pI值相同，均为5.8。HPCE分离证实了同工型IV存在这种电荷微不均一性，但同工型III不存在，并且提供了同工型I和II存在微不均一性的证据。研究了各种电解质缓冲液和运行条件对精氨酸酶同工型HPCE分离的影响。向运行缓冲液中添加0.5 mM亚精胺（SPD）可降低电渗流（EOF），并能够区分天然蛋白质和蛋白质片段。
