Akula, S.; Welinder, C.; Fu, Z.; Olsson, A.-K.; Hellman, L. Identification of the Major Protein Components of Human and Cow Saliva. Int. J. Mol. Sci.2023, 24, 16838.
Akula, S.; Welinder, C.; Fu, Z.; Olsson, A.-K.; Hellman, L. Identification of the Major Protein Components of Human and Cow Saliva. Int. J. Mol. Sci. 2023, 24, 16838.
Akula, S.; Welinder, C.; Fu, Z.; Olsson, A.-K.; Hellman, L. Identification of the Major Protein Components of Human and Cow Saliva. Int. J. Mol. Sci.2023, 24, 16838.
Akula, S.; Welinder, C.; Fu, Z.; Olsson, A.-K.; Hellman, L. Identification of the Major Protein Components of Human and Cow Saliva. Int. J. Mol. Sci. 2023, 24, 16838.
Abstract
Cows produce saliva in very large quantities to lubricate and facilitate food processing. Estimates indicate an amount of 50-150 liter per day. Human saliva has previously been found to contain numerous antibacterial components, such as lysozyme, histatins, members of the S-100 family and lactoferrin to limit pathogen colonization. Cows are dependent of a complex microbial community in their digestive system for food digestion. We wondered how this would influence the content of their saliva. We therefore sampled saliva from five humans and both nose secretions and saliva from six cows and separated the saliva on SDS-PAGE gradient gels and analyzed the major protein bands by LC-MS/MS. The cow saliva was found to be dominated by a few major proteins only, the carbonic anhydrase 6, a pH stabilizing enzyme, and the short palate, lung and nasal epithelium carcinoma-associated protein 2A (SPLUNC2A), also named bovine salivary protein 30kDa (BSP30). This latter protein has been proposed to play a role in local antibacterial response by binding bacterial lipopolysaccharide (LPS) and inhibit bacterial growth, but may instead according to more recent data instead have primarily surfactant activity. Numerous peptide fragments of mucin-5B were also detected in the MS analysis. However, mucins stain poorly by the gel staining solution and they are large and have difficult to enter regular gels why their presence easily are overseen. Interestingly, no major band on gel was detected representing any of the antibacterial proteins indicating that cows may produce them at very low levels not to harm the microbial flora of their digestive system. The nose secretions of the cows primarily contained the odorant protein, a protein thought to be involved in enhancing the sensing of smell by the olfactory receptors to enhance the possibility to quickly sense potential poisonous food components. High levels of secretory IgA was also found in one sample of cow mouth drippings indicating a strong upregulation during an infection. The human saliva we more complex containing both secretory IgA, amylase, carbonic anhydrase 6, lysozyme, histatins and a number of other less abundant proteins.
Keywords
Saliva; IgA; BSP30; PIGR; odorant protein; mucin
Subject
Biology and Life Sciences, Animal Science, Veterinary Science and Zoology
Copyright:
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