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Proceedings of the 31 st European Peptide SymposiumMichal Lebl, Morten Meldal, Knud J. Jensen, Thomas Hoeg-Jensen (Editors)European Peptide Society, 2010Lasiocepsin: Novel Antimicrobial Peptide from the Venom ofEusocial Bee Lasioglossum laticepsLenka Monincová, Jiřina Slaninová, Vladimír Fučík,Oldřich Hovorka, Zdeněk Voburka, Lucie Bednárová, PetrMaloň, and Václav ČeřovskýInstitute of Organic Chemistry and Biochemistry, Academy of Sciences of the CzechRepublic, Flemingovo nám. 2, Prague 6, 166 10, Czech RepublicIntroductionWe have already shown that the venom of wild bees is a rich source of pharmacologicallyinteresting antimicrobial peptides (AMPs). As an example, three linear α-helical AMPsnamed lasioglossins (LL-I, LL-II and LL-III) were identified by us in the venom of the wildeusocial bee Lasioglossum laticeps [1]. Further detailed inspection of the venom extractrevealed the presence of other interesting AMPs. One of those, which we namedlasiocepsin (LAS), is a 27 amino acid residue peptide containing two intramoleculardisulfide bridges (Figure 1). Here we describe its isolation, synthesis, structurecharacterization and biological activities.Results and DiscussionBee specimens of Lasioglossum laticeps were collected in front of our institute in Prague inJune 2009. The venom reservoirs of 10 individuals were removed by dissection and theircontents extracted with a mixture (25 μl) of acetonitrile/water (1:1) containing 0.5% TFA.The extract was fractioned by RP-HPLC (Figure 2). Thecomponents of the peaks detected at 220 nm were analyzedby mass spectrometry and tested for the presence ofantimicrobial activity against Micrococcus luteus (Figure 2,inset). The anti-M. luteus active peptides were subjected toEdman degradation. Three peaks (24, 28 and 29)corresponded to the recently identified lasioglossins (LL-I,LL-II and LL-III) [1]. Two peptides (20, 23), showedsequence and structure similarities to lasioglossins (LL-IVand LL-V). The peptide of the peak numbered 22 showed asignificantly different sequence. We named this peptidelasiocepsin (LAS) and it became the object of our study.Fig. 1. Primary sequenceof Lasiocepsin.mAU250200150100#23LL-V#24#22LL-I #28LASLL-II#20LL-IV#29LL-III#29#20#22 #23 #24#2850010 15 20 25 30 35 40 45 50 55 60t R minFig. 2. RP-HPLC profile of Lasioglossum laticeps venom extract at 220 nm on Vydac C-18 column (205 x 4.6 mm). An elution gradient of solvent from 5% to 70% ofacetonitrile/water/0.1% TFA was applied for 60 min at 1 ml/min flow rate. Inset: Anti-M.luteus activity (clear zones in the drop diffusion test) of individual fractions delineated inthe profile.406