细胞通透性底物(CLIP-Cell)激发波长554nm, 发射波长580nm。CLIP-Cell™ TMR-Star is a photostable red fluorescent substrate that can be used to label CLIP-tag™ fusion proteins inside living cells, on cell surfaces or in vitro. This cell-permeable substrate (BC-TMR) is based on tetramethylrhodamine and is suitable for standard rhodamine filter sets. It has an excitation maximum at 554 nm and emission maximum at 580 nm. This package includes 30 nmol of CLIP-Cell TMR-Star, sufficient to make 10 ml of a 3 µM CLIP-tag fusion protein labeling solution.
The CLIP-tag protein labeling system enables the specific, covalent attachment of virtually any molecule to a protein of interest. CLIP-tag is a protein tag based on human O6-alkylguanine-DNAalkyltransferase (hAGT). CLIP-tag substrates are derivatives of benzylcytosine (BC). In the labeling reaction, the substituted benzyl group of the substrate is covalently attached to the reactive cysteine of CLIP-tag forming a stable thioether bond. Although CLIP-tag is based on the same protein as SNAP-tag®, the benzylcytosine substrates form a separate class of substrates, different from the benzylguanine substrates recognized by SNAP-tag. CLIP-tag and SNAP-tag can be used for orthogonal and complementary labeling of two proteins simultaneously in the same cells.
There are two steps to using this system: subcloning and expression of the protein of interest as a CLIP-tag fusion, and labeling of the fusion with the CLIP-tag substrate of choice. Expression of CLIP-tag fusion proteins is described in the documentation supplied with CLIP-tag plasmids. The labeling of the fusion proteins with the CLIP-tag substrate is described in this document.
细胞通透性底物(CLIP-Cell)激发波长504nm, 发射波长532nm。CLIP-Cell™ 505 is a green fluorescent substrate that can be used to label CLIP-tag™ fusion proteins inside living cells, on cell surfaces or in vitro. This cell-permeable substrate (BC-505) is based on the Dyomics dye DY-505 and is suitable for standard fluorescein filter sets. It has an excitation maximum at 504 nm and emission maximum at 532 nm. This package includes 50 nmol of CLIP-Cell 505 substrate, sufficient to make 10 ml of a 5 µM CLIP-tag fusion protein labeling solution.
The CLIP-tag protein labeling system enables the specific, covalent attachment of virtually any molecule to a protein of interest. CLIP-tag is a protein tag based on human O6-alkylguanine-DNAalkyltransferase (hAGT). CLIP-tag substrates are derivatives of benzylcytosine (BC). In the labeling reaction, the substituted benzyl group of the substrate is covalently attached to the reactive cysteine of CLIP-tag forming a stable thioether bond. Although CLIP-tag is based on the same protein as SNAP-tag®, the benzylcytosine substrates form a separate class of substrates, different from the benzylguanine substrates recognized by SNAP-tag. CLIP-tag and SNAP-tag can be used for orthogonal and complementary labeling of two proteins simultaneously in the same cells.
There are two steps to using this system: subcloning and expression of the protein of interest as a CLIP-tag fusion with the CLIP-tag fusion proteins is described in the documentation supplied with CLIP-tag plasmids. The labeling of the fusion proteins is described in this document.
蛋白质标记系统启动试剂盒提供了标记CLIP-tag融合蛋白的所有必需组份。能在活细胞、固定细胞及体外将红色或绿色荧光基团共价连接到目标蛋白上。每种启动试剂盒包括一个编码所选 tag 的质粒和两种细胞通透性的荧光标记物。试剂盒中还提供一种阳性对照质粒,其编码有亚细胞定位明确的标签蛋白(如:膜蛋白、核蛋白等)。如果必要,试剂盒还会提供一个与目的标签相互作用的、非荧光的阴性对照阻断剂。The SNAP-tag® and CLIP-tag™ are novel tools for the specific, covalent attachment of virtually any molecule to a protein of interest, providing simplicity and extraordinary versatility to the imaging of proteins in live and fixed cells, and to the study of proteins in vitro. The creation of a single gene construct yields a tagged fusion protein capable of forming a covalent linkage to a variety of functional groups, including fluorophores, biotin, or beads. This system provides a powerful and unique tool to study the role of proteins in a variety of highly dynamic processes, including protein trafficking, turnover and complex formation. The CLIP-tag is a 20 kDa mutant of the human DNA repair protein O6-alkylguanine- DNA alkyltransferase (hAGT) that reacts specifically and rapidly with benzylcytosine (BC) derivatives, leading to covalent labeling of the CLIP-tag with a synthetic probe (Figure 1).
The CLIP-tag has a number of features that make it ideal for a variety of protein labeling applications. The rate of the reaction of the CLIP-tag with these derivatives is largely independent of the nature of the synthetic probe attached to BC, permitting the labeling of CLIP fusion proteins with a wide variety of functional groups. Many of these CLIP-tag substrates are cell-permeable, allowing live-cell imaging of protein expression and localization (Figure 2). The ability to turn on the signal at will, together with the availability of a cell-permeable nonfluorescent blocking agent (CLIP-Cell™ Block), allows time-resolved pulse-chase analysis of protein trafficking. Finally, the availability of orthogonal protein labeling systems from NEB permits simultaneous labeling of multiple proteins in a single cell (SNAP-tag, another hAGT variant that reacts exclusively with O6-benzylguanine substrates, and the ACP/MCP tags, small protein tags which can be enzymatically labeled on the cell surface with Coenzyme A derivatives).
The CLIP-Cell Starter Kit contains a mammalian expression plasmid (pCLIPf) encoding the CLIP-tag flanked by restriction sites for cloning a gene of interest, and two cell-permeable fluorescent CLIP-tag substrates. A positive control plasmid (pCLIPf-H2B), encoding a CLIP-tagged protein (histone H2B) with a well-characterized nuclear localization, is also included. Lastly, a negative control “blocking agent” (CLIP-Cell Block) is included that interacts with the CLIP-tag, but is not fluorescent. There are two steps to using this system: subcloning and expression of the protein of interest as a CLIPf fusion, and labeling of the fusion with the CLIP-tag substrate of choice.