文章基本信息

标题：Altered Biochemical Properties of Transient Receptor Potential Vanilloid 6 Calcium Channel by Peptide Tags
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作者：Eun-Jung Park ; Byung-Joo Kim ; Su-Hwa Kim 等
期刊名称：Biological and Pharmaceutical Bulletin
印刷版ISSN：0918-6158
电子版ISSN：1347-5215
出版年度：2009
卷号：32
期号：10
页码：1790-1794
DOI：10.1248/bpb.32.1790
出版社：The Pharmaceutical Society of Japan
摘要：Ion channels are commonly expressed in recombinant forms with peptide tags, which facilitates their molecular and electrophysiological studies. However, peptide tags may alter ion channel properties. Here we describe the differential effect of peptide tags on the biochemical properties of transient receptor potential vanilloid 6 (TRPV6) channels. Yellow fluorescent protein (YFP)-tagged wild-type TRPV6 (YFP-TRPV6^WT) showed much lower levels of aggregate-like bands in Western blots than those of Myc-TRPV6^WT. By contrast, the glycosylation level was higher with Myc-TRPV6^WT than that with YFP-TRPV6^WT. We additionally demonstrate that peptide tags affect the protein integrity of TRPV6 channels. Myc-TRPV6^WT was expressed as an intact channel, whereas the pore mutants Myc-TRPV6^D542A and Myc-TRPV6^D542K were observed to be partially fragmented. By contrast, all YFP-tagged channels were intact, although the YFP-tagged pore mutants were less glycosylated than YFP-TRPV6^WT. However, regardless of the peptide tag used, TRPV6^D542A and TRPV6^D542K electrophysiologically inhibited TRPV6^WT which indicates that all pore mutants are equivalent electrophysiologically, not biochemically. Thus, our findings suggest that peptide tags can produce unintended biochemical changes of ion channels which highlight the necessity of careful biochemical evaluation to clarify the roles of ion channels.
关键词：peptide tag;transient receptor potential vanilloid 6;biochemical property;ion channel