title: Characterization of neutral lipase BT-1 isolated from the labial gland of Bombus terrestris males.
abstract: BACKGROUND
  In addition to their general role in the hydrolysis of storage lipids, bumblebee lipases can participate in the biosynthesis of fatty acids that serve as precursors of pheromones used for sexual communication.
  
  
  RESULTS
  We studied the temporal dynamics of lipolytic activity in crude extracts from the cephalic part of Bombus terrestris labial glands. Extracts from 3-day-old males displayed the highest lipolytic activity. The highest lipase gene expression level was observed in freshly emerged bumblebees, and both gene expression and lipase activity were lower in bumblebees older than 3 days. Lipase was purified from labial glands, further characterized and named as BT-1. The B. terrestris orthologue shares 88% sequence identity with B. impatiens lipase HA. The molecular weight of B. terrestris lipase BT-1 was approximately 30 kDa, the pH optimum was 8.3, and the temperature optimum was 50°C. Lipase BT-1 showed a notable preference for C8-C10 p-nitrophenyl esters, with the highest activity toward p-nitrophenyl caprylate (C8). The Michaelis constant (Km) and maximum reaction rate (Vmax) for p-nitrophenyl laurate hydrolysis were Km = 0.0011 mM and Vmax = 0.15 U/mg.
  
  
  CONCLUSIONS
  This is the first report describing neutral lipase from the labial gland of B. terrestris. Our findings help increase understanding of its possible function in the labial gland.
authors.affiliation: Institute of Organic Chemistry and Biochemistry AS CR, Prague, Czech Republic.
authors.forename: Jana
authors.initials: J
authors.lastname: Brabcová
authors.forename: Darina
authors.initials: D
authors.lastname: Prchalová
authors.forename: Zuzana
authors.initials: Z
authors.lastname: Demianová
authors.forename: Alena
authors.initials: A
authors.lastname: Bučánková
authors.forename: Heiko
authors.initials: H
authors.lastname: Vogel
authors.forename: Irena
authors.initials: I
authors.lastname: Valterová
authors.forename: Iva
authors.initials: I
authors.lastname: Pichová
authors.forename: Marie
authors.initials: M
authors.lastname: Zarevúcka
mesh_terms: D000818:Animals; D001516:Bees / Q000235:genetics / Q000378:metabolism*; D005227:Fatty Acids / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression / Q000235:genetics; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D008049:Lipase / Q000235:genetics / Q000378:metabolism*; D008297:Male; D010675:Pheromones / Q000235:genetics / Q000378:metabolism; D013379:Substrate Specificity
chemical_list: D005227:Fatty Acids; D010675:Pheromones; D008049:Lipase