Esterase and lipase in camel tick Hyalomma dromedarii (Acari: Ixodidae) during embryogenesis.
Esterase and lipase activity showed significant changes during embryogenesis of camel tick Hyalomma dromedarii. From the elution profile of chromatography on DEAE-cellulose, six forms of H. dromedarii esterase (El to EVI) can be distinguished. Esterase EIII was purified to homogeneity after chromatography on Sepharose 6B. The molecular mass of esterase EIII was 45 kDa for the native enzyme and represented a monomer of 45 kDa by SDS-PAGE. Esterase EIII had an acidic pI at 5.3. Lipase activity was detected in the same DEAE-cellulose peaks (LI to LVI) of H. dromedarii esterases. The highest lipase activity was exhibited by lipase LIII. Esterase EIII and lipase LIII were compared with respect to Michaelis constant, substrate specificity, temperature optimum, heat stability, pH optimum, effect of metal ions and inhibitors. This study suggests that H. dromedarii lipolytic enzymes may play a central role in the interconversion of lipovitellins during embryogenesis.
Molecular Biology Department, National Research Centre, Cairo, Egypt.
Afaf S
AS
Fahmy
Somia S
SS
Abdel-Gany
Tarek M
TM
Mohamed
Saleh A
SA
Mohamed
D000818:Animals; D002162:Camelus / Q000469:parasitology*; D004075:Diglycerides / Q000378:metabolism; D004527:Egg Proteins; D015387:Egg Proteins, Dietary / Q000378:metabolism; D004625:Embryo, Nonmammalian / Q000201:enzymology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004950:Esterases / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000302:isolation & purification*; D007527:Isoenzymes / Q000737:chemistry / Q000302:isolation & purification; D026863:Ixodidae / Q000196:embryology / Q000201:enzymology; D007605:Juvenile Hormones / Q000378:metabolism; D007700:Kinetics; D008049:Lipase / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000302:isolation & purification*; D008670:Metals / Q000378:metabolism; D013379:Substrate Specificity
D004075:Diglycerides; D004527:Egg Proteins; D015387:Egg Proteins, Dietary; D004791:Enzyme Inhibitors; D007527:Isoenzymes; D007605:Juvenile Hormones; D008670:Metals; C001549:lipovitellin; D004950:Esterases; D008049:Lipase