Peptides tagging

Kobayashi, T., Shiratori, M., Nakano, H., Eguchi, C., Shirai, M., Naka, D. and Shibui, T. (2007). Short peptide tags increase the yield of C-terminally labeled protein. Biotechnol. Lett. 29, 1065-73. 

In the absence of further targeting information, the expressed protein is secreted to the apoplast. The stability of antibodies in the apoplast is lower than in the lumen of the ER. Therefore, antibody expression levels can be increased up to ten times higher if the protein is retrieved to the ER lumen using an H/KDEL C-terminal tetra-peptide tag [133]. Again, although the principles of ER-retention in molecular farming have been established using antibodies, it is likely that they will also apply to many other proteins. 

Like FRET, today BRET is predominantly used in biological sciences, especially in the monitoring of protein-protein interactions such as hormone-receptor interaction [223, 224] and protein-DNA interaction in living systems. However, BL resonance energy transfer can also be applied in immunoassays by using for instance a peptide-tagged luciferase and a fluorescein-labeled antipeptide antibody [225]. The development of more BRET assays for small-molecule analytes is thus awaited. 

ELISA for the antibody fragments either detects a peptide tag (for scFv and... 

Cull, M. G. and Schatz, P. J. (2000) Biotinylation of proteins in vivo and in vitro using small peptide tags. Methods Enzymol. 326, 430-440. 

Fig. 4. Role of the stop codon and lOSa-RNA in E. coli translation. (A) When a stop codon is encountered, a complex of two release factors, RF-1 and RF-3 or RF-2 and RF-3, binds instead of the tRNA. The release factor RF-1 recognizes the stop codons UAA and UAG, while RF-2 recognizes UAA and UGA. The binding of the release factor complex results in hydrolysis of the peptidyl-tRNA and release of the peptide. (B) The role of lOSa-RNA. If truncated mRNA without a stop codon is translated in E. coli, the ribosome stops at the end of the mRNA. lOSa-RNA can then bind to the ribosomal A site and lOSa-RNA can act as tRNA by transferring an alanine to the truncated protein. Subsequently, lOSa-RNA acts as mRNA and a peptide tag with the indicated sequence is added to the truncated protein. lOSa-RNA encodes a stop codon and therefore the protein is released and then degraded by proteases specifically recognizing this C-terminal tag.

Nucleotide tags Peptide tags Haloaromatic tags Secondary amine tags Isotopic tags Autotagging... 

Evans, W.J., Allen, N.T., and Ziller, J.W. (2002) Protein affinity labeling mediated by genetically encoded peptide tags. Angewandte Chemie International Edition, 41, 359. 

Yin J, Straight PD, McLoughlin SM, Zhou Z, Lin AJ, Golan DE, Kelleher NL, Kolter R, Walsh CT. Genetically encoded short peptide tag for versatile protein labehng by Sfp phosphopantetheinyl transferase. Proc. Natl. Sci. U.S.A. 2005 102 15815-15820. 

Keiler KC, Waller PR, Sauer RT. Role of a peptide tagging system in degradation of proteins synthesized from damaged messenger RNA. Science 1996 271(5251) 990-993. 

E.F. Strittmatter, P.L. Ferguson, K. Tang, R.D. Smith, Proteome analyses using accurate mass and elution time peptide tags with capillary LC-TOF-MS, J. Am. Soc. Mass Spectrom., 14 (2003) 980. 

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