Invertase

Invertase is an enzyme that catalyzes the hydrolysis (breakdown) of sucrose (table sugar) into fructose and glucose.[1][2] Alternative names for invertase include EC 3.2.1.26, saccharase, glucosucrase, beta-h-fructosidase, beta-fructosidase, invertin, sucrase, maxinvert L 1000, fructosylinvertase, alkaline invertase, acid invertase, and the systematic name: beta-fructofuranosidase. The resulting mixture of fructose and glucose is called inverted sugar syrup. Related to invertases are sucrases. Invertases and sucrases hydrolyze sucrose to give the same mixture of glucose and fructose. Invertases cleave the O-C(fructose) bond, whereas the sucrases cleave the O-C(glucose) bond.[3]

Invertase
Identifiers
EC number3.2.1.26
CAS number9001-57-4
Databases
IntEnzIntEnz view
BRENDABRENDA entry
ExPASyNiceZyme view
KEGGKEGG entry
MetaCycmetabolic pathway
PRIAMprofile
PDB structuresRCSB PDB PDBe PDBsum

For industrial use, invertase is usually derived from yeast. It is also synthesized by bees, which use it to make honey from nectar. Optimal temperature at which the rate of reaction is at its greatest is 60 °C and an optimum pH of 4.5.[3] Typically, sugar is inverted with sulfuric acid.

Applications and examples

Invertase is expensive, so it may be preferable to make fructose from glucose using glucose isomerase, instead.

Chocolate-covered cherries,[4] other cordials, and fondant candies include invertase, which liquefies the sugar. Once the candy is manufactured, it needs at least a few days to a few weeks in storage so the invertase has time to break down the sucrose.[5]

Inhibition

Urea acts as a non-competitive inhibitor of invertase, presumably by breaking the intramolecular hydrogen bonds contributing to the tertiary structure of the enzyme.[6][7]

See also

References
  1. Myrbäck K (1960). "Invertases". In Boyer PD, Lardy H, Myrbäck K (eds.). The Enzymes. 4 (2nd ed.). New York: Academic Press. pp. 379–396.
  2. Neumann NP, Lampen JO (February 1967). "Purification and properties of yeast invertase". Biochemistry. 6 (2): 468–75. doi:10.1021/bi00854a015. PMID 4963242.
  3. Schiweck, Hubert; Clarke, Margaret; Pollach, Günter (2007). "Sugar". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a25_345.pub2. ISBN 978-3527306732.
  4. LaBau E. "Chocolate-Covered Cherries". About.com Candy. Retrieved December 6, 2012.
  5. LaBau E. "What is Invertase?". About.com. Retrieved 10 April 2015.
  6. Chase, Aurin M.; Von Meier, Hildegard C.; Menna, Vincent J. (February 1962). "The Non-Competitive Inhibition and Irreversible Inactivation of Yeast Invertase by Urea". Journal of Cellular and Comparative Physiology. 59 (1): 1–13. doi:10.1002/jcp.1030590102. ISSN 0095-9898. PMID 13878348.
  7. Rajagopalan, K. V.; Fridovich, Irwin; Handler, Philip (1961-04-01). "Competitive Inhibition of Enzyme Activity by Urea". Journal of Biological Chemistry. 236 (4): 1059–1065. ISSN 0021-9258. PMID 13739212.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.