| Lingual lipase | |
|---|---|
 Lingual Lipase with catalytic triad highlighted in center | |
| Identifiers | |
| Symbol | LIPF |
| Alt. names | Triacylglycerol, |
| Other data | |
| EC number | 3.1.1.3 |
Lingual lipase is a member of a family of digestive enzymes called triacylglycerol lipases, EC 3.1.1.3, that use the catalytic triad of aspartate, histidine, and serine to hydrolyze medium and long-chain triglycerides into partial glycerides and free fatty acids. The enzyme, released into the mouth along with the saliva, catalyzes the first reaction in the digestion of dietary lipid, with diglycerides being the primary reaction product.[1] However, due to the unique characteristics of lingual lipase, including a pH optimum 4.5–5.4 and its ability to catalyze reactions without bile salts, the lipolytic activity continues through to the stomach.[2] Enzyme release is signaled by autonomic nervous system after ingestion, at which time the serous glands under the circumvallate and foliate lingual papillae on the surface of the tongue[3] secrete lingual lipase to the grooves of the circumvallate and foliate papillae, co-localized with fat taste receptors. The hydrolysis of the dietary fats is essential for fat absorption by the small intestine, as long chain triacylglycerides cannot be absorbed, and as much as 30% of fat is hydrolyzed within 1 to 20 minutes of ingestion by lingual lipase alone.[2]
Lingual lipase, together with gastric lipase, comprise the two acidic lipases.
- ^ Hamosh M, Scow RO (January 1973). "Lingual lipase and its role in the digestion of dietary lipid". The Journal of Clinical Investigation. 52 (1): 88–95. doi:10.1172/JCI107177. PMC 302230. PMID 4682389.
- ^ a b Cleghorn GJ, Shepherd RW (1989). Cystic fibrosis: nutritional and intestinal disorders. Boca Raton: CRC Press. ISBN 978-0-8493-6954-4.
- ^ Chandrashekar J, Hoon MA, Ryba NJ, Zuker CS (November 2006). "The receptors and cells for mammalian taste". Nature. 444 (7117): 288–94. doi:10.1038/nature05401. PMID 17108952.