Abstract
We describe a phospholipase A2 (PLA2) associated with the salivary glands of tobacco hornworms, Manduca sexta. This enzyme is able to hydrolyze arachidonic acid from the sn-2 position of PLs. Addition of the calcium chelator, EGTA, or calcium, to the Tris reaction buffer impaired the PLA2 activity, from which we infer the enzyme requires very low concentrations of calcium or perhaps other ions for optimal activity. PLA2 activity was sensitive to protein concentration (highest activity at 25 microg protein per microl), reaction time (optimal at 30 min), buffer pH (optimal at pH 8-10), and reaction temperature (optimal range 18-38 degrees C). The salivary gland PLA2 was sensitive to the site-specific inhibitor, oleyloxyethylphosphorylcholine and stable to freezing at -80 degrees C, but not -20 degrees C. The biological significance of this enzyme may relate to hydrolysis of fatty acid moieties from dietary PLs for absorption by midgut epithelia. This salivary gland enzyme may also be responsible for killing food-borne bacteria.
References
Mar 31, 1989·Science·B A KeddieL E Volkman
Jan 1, 1993·Archives of Insect Biochemistry and Physiology·J M Uscian, D W Stanley-Samuelson
Apr 23, 1993·Biochimica Et Biophysica Acta·L J ReynoldsE A Dennis
Jan 1, 1997·Trends in Biochemical Sciences·E A Dennis
May 20, 1999·Annual Review of Pharmacology and Toxicology·J BalsindeE A Dennis
Nov 18, 2000·Biochimica Et Biophysica Acta·D A Six, E A Dennis
Nov 6, 2001·The Journal of Biological Chemistry·Rao S KoduriMichael H Gelb
Nov 14, 2001·The Journal of Biological Chemistry·Stephen A BeersDavid C Wilton
Dec 19, 2002·Archives of Insect Biochemistry and Physiology·Hasan TunazDavid W Stanley
May 29, 2003·Journal of Insect Physiology·D W. StanleyR L. Rana
May 17, 2005·Insect Biochemistry and Molecular Biology·J McGettiganJ A T Dow
Citations
Oct 1, 1994·Proteins·J H MatthewsA B Mukherjee
Dec 2, 2011·Journal of Parasitology Research·Mário A C Silva-NetoGeorgia C Atella
Nov 3, 2011·PloS One·Maria de la Paz Celorio-ManceraHeiko Vogel
Nov 19, 2013·PloS One·Rui JiYonggen Lou
Nov 26, 2008·Journal of Insect Physiology·Richard H ShukleMing-Shun Chen
Sep 7, 2012·Archives of Insect Biochemistry and Physiology·Mohammad Saadati BezdiSetsuko Komatsu
Dec 17, 2009·Insect Molecular Biology·J T ChristellerR M Simpson
Jul 29, 2006·Comparative Biochemistry and Physiology. Toxicology & Pharmacology : CBP·S NagarajuK Kemparaju
Jul 11, 2006·Biochimica Et Biophysica Acta·David Stanley
Sep 24, 2013·Biochimica Et Biophysica Acta·M S DefferrariC R Carlini
Jun 28, 2011·Journal of Insect Physiology·John T ChristellerFrédéric Carrière
Oct 16, 2012·Journal of Insect Physiology·Bridget DeLayWilliam Lamp
Apr 18, 2018·Insect Molecular Biology·S HeD P McMahon
Aug 25, 2016·Genome Biology and Evolution·Gilbert SmithAdriana D Briscoe
Feb 23, 2019·Frontiers in Physiology·David Stanley, Yonggyun Kim
Nov 24, 2020·BMC Genomics·Vinod Kumar PrajapatiJyothilakshmi Vadassery