Biology:Proline rich protein

From HandWiki

Proline-rich proteins (PRPs) is a class of intrinsically unstructured proteins[1] (IUP) containing several repeats of a short proline-rich sequence. Many tannin-consuming animals secrete a tannin-binding protein (mucin) in their saliva. Tannin-binding capacity of salivary mucin is directly related to its proline content. Advantages in using salivary proline-rich proteins (PRPs) to inactivate tannins are :

  • PRPs inactivate tannins to a greater extent than do dietary proteins; this results in reduced fecal nitrogen losses,[2]
  • PRPs contain non specific nitrogen and nonessential amino acids; this makes them more convenient for an animal to exploit rather than using up valuable dietary protein.[3]

Example of this class of protein is IB5, a human parotid salivary protein known to bind with polyphenols (binding responsible for the astringency mouth feel). Other examples include Proline-Rich 12, Proline-Rich Protein 30, and Proline-Rich Protein 21.

References

  1. Canon, Francis; Paté, Franck; Meudec, Emmanuelle; Marlin, Thérèse; Cheynier, Véronique; Giuliani, Alexandre; Sarni-Manchado, Pascale (2009). "Characterization, stoichiometry, and stability of salivary protein–tannin complexes by ESI-MS and ESI-MS/MS". Analytical and Bioanalytical Chemistry 395 (8): 2535–2545. doi:10.1007/s00216-009-3180-3. PMID 19838685. https://doi.org/10.1007%2Fs00216-009-3180-3. 
  2. de Wijk, René A.; Prinz, Jon F. (2005). "The role of friction in perceived oral texture". Food Quality and Preference 16 (2): 121–129. doi:10.1016/j.foodqual.2004.03.002. https://www.sciencedirect.com/science/article/abs/pii/S0950329304000321. 
  3. "Tanins chemistry on www.users.muohio.edu". http://www.users.muohio.edu/hagermae/tannin.pdf.