Species-specific peptides

Alternatively, species-specific peptides can be targeted and partially sequenced to confirm the presence or absence of microorganisms of high interest. 

FIGURE 1 Proteomics pipeline used for the identification, characterization, and detection of species-specific peptide biomarkers for fish authentication purposes. 

Williams DD, Benedek O, Turnbough CL, Jr. Species-specific peptide ligands for the detection of Bacillus anthracis spores. Appl Environ Microbiol 2003 69 6288-6293. 

Akin to the findings with ICP47, gpUS6-mediated inhibition of TAP is species specific. Peptide translocation assays using cells infected with a gpUS6-recombinant vaccinia virus showed that TAP in human, monkey, and rabbit cells could be inhibited whereas mouse and rat TAP were unaffected (F. Momberg and H. Hengel, manuscript in preparation). 

Figure 12.4 MALDI analysis of peptides prepared in situ from a 10 1 mixture of Bacillus cereus and Bacillus anthracis sp. Sterne.82 (a) Survey spectrum of peptide products. Species assignments are indicated on the figure. (b) Spectrum of fragment ions produced by low-energy collisions of the Bacillus cereus-specific peptide of mass 1529. (c) Spectrum of fragment ions produced by low-energy collisions of ions of the Bacillus anthracis peptide of mass 1528.

The appropriateness of testing a human-specific peptide hormone in nonhuman species ... 

Proteins are polymers of amino acids linked together by peptide bonds the same family of 20 amino acids is employed by all living organisms to construct their proteins. The sequence of amino acids along the chain defines the primary structure of the protein, a species-specific quality. 

Polatajko, A., Encinar, J. R., Schaumloffel, D., and Szpunar, J., Quantification of a selenium-containing protein in yeast extract via an accurate determination of a tryptic peptide by species-specific isotope dilution capillary HPLC-ICP MS, Chemia Analityczna 50(1), 265-278, 2005. 

Insulin therefore consists of two peptide chains that are connected by two disulfide bonds, since the C-peptide is cleaved off. There are some species-specific differences in the amino acid sequence of the hormone. X-ray diffraction studies have shown that insulin occurs as a hexameric protein containing two Zn atoms. The dimers are first held by four hydrogen bonds and a hydrophobic bond along the sequence in the form of an antiparallel P sheet. The dimers then bind by interaction of the B -Ala, B -Leu, and B -Val residues. The core of the hexamer contains water. 

Both the human and the murine IFN-y receptors consist of a ligand-binding subunit and a species-specific cofactor molecule. It is through interaction with this cell-surface receptor complex that IFN-y exerts its biological effects. The IFN-y molecule and its N-terminal peptide IFN-y (1-39) bind specifically to the... 

The specific peptide composition can be used to characterize foods. Abe (124) separated the peptides carnosine, anserine, and balenine from the white and red muscle of nine species of marine fishes. Carnegie et al. (37,38) developed an HPLC method using a Partisil-lOSCX column with 0.2 M lithium formate at a pH of 2.9 and a temperature of 40°C under isocratic conditions with postcolumn derivatization using OPA to separate the dipeptides of histidine, anserine, carnosine, and balenine from the muscles of various species (pork, chicken, beef, lamb, and mutton) in order to identify the origin of the meat used in meat products. The concentration of balenine and the balenineranserine ratio were higher in pork than in the other meats, and these relationships were useful in determining the presence of pork in mixtures with other meats. 

Banks, W.A., J.B. Jaspan, and A.J. Kastin. 1997. Selective, physiological transport of insulin across the blood-brain barrier Novel demonstration by species-specific radioimmunoassays. Peptides 18 1257. 

Human ACTH is a single peptide chain of 39 amino acids. The amino terminal portion containing amino acids 1-24 is necessary for full biologic activity. The remaining amino acids (25-39) confer species specificity. Synthetic human ACTHi 24 is known as cosyntropin. The amino terminal amino acids 1-13 are identical to melanocyte-stimulating hormone (cr-MSH), which has been found in animals but not in humans. In states of excessive pituitary ACTH secretion (Addison s disease or an ACTH-secreting pituitary tumor), hyperpigmentation—caused by the -MSH activity intrinsic to ACTH—may be noted. 

Peptides and proteins exhibit distinct species specificity with regard to structure and activity. Peptides and proteins with identical physiological function may have different amino acid sequences in different species, and may have no activity or be even immunogenic if used in a different species. 

The same amidation reaction was employed by Joshi et al. to covalently functionalize MWNTs with a specific peptide sequence, which specifically binds to the heptameric receptor-binding subunit of anthrax toxin.33 These nanotube-peptide conjugates were found to selectively destroy anthrax toxin with the reactive oxygen species generated by the nanotubes upon near-IR radiation.33... 

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