Antimicrobial peptides from saliva
They are in major secretion-submandibular gland:
Sublingual and parotid glands.
Minor salivary glands-lingual, buccal and labials glands.
– Lysozyme and lactotransferrin from both major and minor salivary glands
Salivary lysozyme is able to hydrolyze beta (1-4) bonds between a N-actelmuramic acid and a N-acetylglucosamine in the peptidoglycan layer of the bacterial cell wall.
→ Lysozyme protects us from ever-present danger of bacterial infection.
It is a small enzyme which attacks the protective cell walls go bacteria. It can breaks carbohydrate chains, destroying the structural integrity of the cell wall.
The bacteria burst under their own internal pression (1).
Also, Transferrin-cationic peptides have a great function. They bind iron thus hindering bacterial growth.
→ Lactotransferrin is found in the secondary granules of neutrophils.
The protein is a major iron-binding protein.
In fact, Iron (III) is no soluble, and it is incorporates by transferrin which cross the membrane layer and reducts into iron (II) . Thanks to a proton gradient into an endosome membrane , the pH decreases from 7 to 5,6 and ATP is hydrolyzed into ADP and Pi. Consequently, Iron (II) is able to be stocked into ferritine.
This protein demonstrates a broad spectrum of properties, including (2) :
- Regulation of iron homeostasis
- Regulation of cellular growth
- Differentiation and protection against cancer development and metastasis.