首页 | 本学科首页   官方微博 | 高级检索  
     


Substrate specificity of a chimera made from Xenopus SGLT1-like protein and rabbit SGLT1
Authors:Katsumi Nagata  Yoshio Hata
Affiliation:Department of Biomedical Science, Institute of Regenerative Medicine and Biofunction, Tottori University Graduate School of Medical Science, Nishimachi 86, Yonago 683-8503, Japan
Abstract:
To characterize the sugar translocation pathway of Na+/glucose cotransporter type 1 (SGLT1), a chimera was made by substituting the extracellular loop between transmembrane domain (TM) 12 and TM13 of Xenopus SGLT1-like protein (xSGLT1L) with the homologous region of rabbit SGLT1. The chimera was expressed in Xenopus oocytes and its transport activity was measured by the two-microelectrode voltage-clamp method. The substrate specificity of the chimera was different from those of xSGLT1L and SGLT1. In addition the chimera's apparent Michaelis-Menten constant (Km) for myo-inositol, 0.06 mM, was about one fourth of that of xSGLT1L, 0.25 mM, while the chimera's apparent Km for d-glucose, 0.8 mM, was about one eighth of that of xSGLT1L, 6.3 mM. Our results suggest that the extracellular loop between TM12 and TM13 participates in the sugar transport of SGLT1.
Keywords:Xenopus SGLT1-like protein   SGLT   SMIT   Chimera
本文献已被 ScienceDirect 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号