Reactive α,β-unsaturated aldehydes, including 4-oxoalk-2-enals, are known to be present in volatile secretions of numerous heteropteran insect species. Because the aldehydes are likely to originate from metabolism of fatty acids (FAs), the present study aimed to examine and compare the aldehyde and FA profiles of four model heteropteran species. The model species consisted of adult family group representatives within the infraorder Pentatomomorpha (Hemiptera: Heteroptera): seed bug (Lygaeus equestris (Lygaeoidea)), dock leaf bug (Coreus marginatus (Coreoidea)), red firebug (Pyrrhocoris apterus (Pyrrhocoroidea)), and European stink bug (Graphosoma lineatum (Pentatomoidea)). Solid-phase microextraction combined with two-dimensional gas-chromatography/time-of-flight mass spectrometry was used to establish the profiles of volatile secretions in stressed living insects. The FA profiles of acylglyceride and phospholipid fractions deposited in fat body and/or hemolymph were obtained by liquid chromatography/mass spectrometry and gas chromatography with flame ionization detection techniques. Our results based on multivariate statistical analyses of the data imply that volatile secretion blends as well as fat body and/or hemolymph lipid profiles are species specific but the differences in volatile blends between different species do not mirror the changes in corresponding fat body and/or hemolymph lipid profiles of stressed and non-stressed individuals.
- MeSH
- aldehydy analýza MeSH
- druhová specificita MeSH
- fyziologický stres MeSH
- hemolymfa MeSH
- Heteroptera chemie MeSH
- mastné kyseliny analýza MeSH
- mikroextrakce na pevné fázi MeSH
- plynová chromatografie s hmotnostně spektrometrickou detekcí MeSH
- tukové těleso MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Three novel antimicrobial peptides (AMPs), named panurgines (PNGs), were isolated from the venom of the wild bee Panurgus calcaratus. The dodecapeptide of the sequence LNWGAILKHIIK-NH₂ (PNG-1) belongs to the category of α-helical amphipathic AMPs. The other two cyclic peptides containing 25 amino acid residues and two intramolecular disulfide bridges of the pattern Cys8-Cys23 and Cys11-Cys19 have almost identical sequence established as LDVKKIICVACKIXPNPACKKICPK-OH (X=K, PNG-K and X=R, PNG-R). All three peptides exhibited antimicrobial activity against Gram-positive bacteria and Gram-negative bacteria, antifungal activity, and low hemolytic activity against human erythrocytes. We prepared a series of PNG-1 analogs to study the effects of cationicity, amphipathicity, and hydrophobicity on the biological activity. Several of them exhibited improved antimicrobial potency, particularly those with increased net positive charge. The linear analogs of PNG-K and PNG-R having all Cys residues substituted by α-amino butyric acid were inactive, thus indicating the importance of disulfide bridges for the antimicrobial activity. However, the linear PNG-K with all four cysteine residues unpaired, exhibited antimicrobial activity. PNG-1 and its analogs induced a significant leakage of fluorescent dye entrapped in bacterial membrane-mimicking large unilamellar vesicles as well as in vesicles mimicking eukaryotic cell membrane. On the other hand, PNG-K and PNG-R exhibited dye-leakage activity only from vesicles mimicking bacterial cell membrane.
- MeSH
- antibakteriální látky chemie farmakologie MeSH
- antifungální látky chemie farmakologie MeSH
- hydrofobní a hydrofilní interakce MeSH
- Hymenoptera metabolismus MeSH
- kationické antimikrobiální peptidy chemie metabolismus farmakologie MeSH
- lidé MeSH
- mikrobiální testy citlivosti MeSH
- povrchově aktivní látky MeSH
- sekvence aminokyselin MeSH
- sekvenční analýza proteinů MeSH
- unilamelární lipozómy metabolismus MeSH
- včelí jedy chemie metabolismus farmakologie MeSH
- vztahy mezi strukturou a aktivitou MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
In the venom of eusocial bee Lasioglossum laticeps, we identified a novel unique antimicrobial peptide named lasiocepsin consisting of 27 amino acid residues and two disulfide bridges. After identifying its primary structure, we synthesized lasiocepsin by solid-phase peptide synthesis using two different approaches for oxidative folding. The oxidative folding of fully deprotected linear peptide resulted in a mixture of three products differing in the pattern of disulfide bridges. Regioselective disulfide bond formation significantly improved the yield of desired product. The synthetic lasiocepsin possessed antimicrobial activity against both Gram-positive and -negative bacteria, antifungal activity against Candida albicans, and no hemolytic activity against human erythrocytes. We synthesized two lasiocepsin analogs cyclized through one native disulfide bridge in different positions and having the remaining two cysteines substituted by alanines. The analog cyclized through a Cys8-Cys25 disulfide bridge showed reduced antimicrobial activity compared to the native peptide while the second one (Cys17-Cys27) was almost inactive. Linear lasiocepsin having all four cysteine residues substituted by alanines or alkylated was also inactive. That was in contrast to the linear lasiocepsin with all four cysteine residues non-paired, which exhibited remarkable antimicrobial activity. The shortening of lasiocepsin by several amino acid residues either from the N- or C-terminal resulted in significant loss of antimicrobial activity. Study of Bacillus subtilis cells treated by lasiocepsin using transmission electron microscopy showed leakage of bacterial content mainly from the holes localized at the ends of the bacterial cells.
- MeSH
- antibakteriální látky chemická syntéza chemie farmakologie MeSH
- antifungální látky chemická syntéza chemie farmakologie MeSH
- Candida albicans účinky léků MeSH
- cyklické peptidy chemická syntéza chemie farmakologie MeSH
- cystin chemická syntéza chemie MeSH
- erytrocyty účinky léků MeSH
- gramnegativní bakterie účinky léků MeSH
- grampozitivní bakterie účinky léků ultrastruktura MeSH
- hemolýza MeSH
- lidé MeSH
- mikrobiální testy citlivosti MeSH
- molekulární sekvence - údaje MeSH
- sekundární struktura proteinů MeSH
- sekvence aminokyselin MeSH
- sekvenční analýza proteinů MeSH
- včelí jedy chemická syntéza chemie farmakologie MeSH
- včely chemie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Two novel antimicrobial peptides, named halictines, were isolated from the venom of the eusocial bee Halictus sexcinctus. Their primary sequences were established by ESI-QTOF mass spectrometry, Edman degradation and enzymatic digestion as Gly-Met-Trp-Ser-Lys-Ile-Leu-Gly-His-Leu-Ile-Arg-NH2 (HAL-1), and Gly-Lys-Trp-Met-Ser-Leu-Leu-Lys-His-Ile-Leu-Lys-NH2 (HAL-2). Both peptides exhibited potent antimicrobial activity against Gram-positive and Gram-negative bacteria but also noticeable hemolytic activity. The CD spectra of HAL-1 and HAL-2 measured in the presence of trifluoroethanol or SDS showed ability to form an amphipathic alpha-helical secondary structure in an anisotropic environment such as bacterial cell membrane. NMR spectra of HAL-1 and HAL-2 measured in trifluoroethanol/water confirmed formation of helical conformation in both peptides with a slightly higher helical propensity in HAL-1. Altogether, we prepared 51 of HAL-1 and HAL-2 analogs to study the effect of such structural parameters as cationicity, hydrophobicity, alpha-helicity, amphipathicity, and truncation on antimicrobial and hemolytic activities. The potentially most promising analogs in both series are those with increased net positive charge, in which the suitable amino acid residues were replaced by Lys. This improvement basically relates to the increase of antimicrobial activity against pathogenic Pseudomonas aeruginosa and to the mitigation of hemolytic activity.
- MeSH
- antibakteriální látky chemie izolace a purifikace farmakologie MeSH
- Bacteria účinky léků MeSH
- erytrocyty účinky léků MeSH
- hemolýza účinky léků MeSH
- hemolyziny chemie izolace a purifikace farmakologie MeSH
- kationické antimikrobiální peptidy chemie izolace a purifikace farmakologie MeSH
- krysa rodu rattus MeSH
- molekulární sekvence - údaje MeSH
- sekundární struktura proteinů MeSH
- sekvence aminokyselin MeSH
- včelí jedy chemie MeSH
- včely chemie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Three novel structurally related pentadecapeptides, named lasioglossins, were isolated from the venom of the eusocial bee Lasioglossum laticeps. Their primary sequences were established as H-Val-Asn-Trp-Lys-Lys-Val-Leu-Gly-Lys-Ile-Ile-Lys-Val-Ala-Lys-NH(2) (LL-I), H-Val-Asn-Trp-Lys-Lys-Ile-Leu-Gly-Lys-Ile-Ile-Lys-Val-Ala-Lys-NH(2) (LL-II) and H-Val-Asn-Trp-Lys-Lys-Ile-Leu-Gly-Lys-Ile-Ile-Lys-Val-Val-Lys-NH(2) (LL-III). These lasioglossins exhibited potent antimicrobial activity against both Gram-positive and Gram-negative bacteria, low haemolytic and mast cell degranulation activity, and a potency to kill various cancer cells in vitro. The lasioglossin CD spectra were measured in the presence of trifluoroethanol and sodium dodecyl sulfate solution and indicated a high degree of alpha-helical conformation. NMR spectroscopy, which was carried out in trifluoroethanol/water confirmed a curved alpha-helical conformation with a concave hydrophobic and convex hydrophilic side. To understand the role of this bend on biological activity, we studied lasioglossin analogues in which the Gly in the centre of the molecule was replaced by other amino acid residues (Ala, Lys, Pro). The importance of the N-terminal part of the molecule to the antimicrobial activity was revealed through truncation of five residues from both the N and C termini of the LL-III peptide. C-terminal deamidation of LL-III resulted in a drop in antimicrobial activity, but esterification of the C terminus had no effect. Molecular modelling of LL-III and the observed NOE contacts indicated the possible formation of a bifurcated H-bond between hydrogen from the Lys15 CONH peptide bond and one H of the C-terminal CONH(2) to the Ile11 oxygen atom. Such interactions cannot form with C-terminal esterification.
- MeSH
- antiinfekční látky farmakologie chemická syntéza chemie MeSH
- antitumorózní látky farmakologie chemická syntéza chemie MeSH
- gramnegativní bakterie účinky léků MeSH
- grampozitivní bakterie účinky léků MeSH
- hemolýza účinky léků MeSH
- kationické antimikrobiální peptidy farmakologie chemie MeSH
- léky antitumorózní - screeningové testy MeSH
- lidé MeSH
- magnetická rezonanční spektroskopie MeSH
- mastocyty metabolismus účinky léků MeSH
- mikrobiální testy citlivosti MeSH
- nádorové buněčné linie MeSH
- peptidy farmakologie chemická syntéza chemie MeSH
- proliferace buněk účinky léků MeSH
- včelí jedy chemie MeSH
- včely chemie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- práce podpořená grantem MeSH
A novel antimicrobial peptide designated melectin was isolated from the venom of the cleptoparasitic bee Melecta albifrons. Its primary sequence was established as H-Gly-Phe-Leu-Ser-Ile-Leu-Lys-Lys-Val-Leu-Pro-Lys-Val-Met-Ala-His-Met-Lys-NH(2) by Edman degradation and ESI-QTOF mass spectrometry. Synthetic melectin exhibited antimicrobial activity against both gram-positive and -negative bacteria and it degranulated rat peritoneal mast cells, but its hemolytic activity was low. The CD spectra of melectin measured in the presence of trifluoroethanol and sodium dodecyl sulfate showed a high content alpha-helices, which indicates that melectin can adopt an amphipathic alpha-helical secondary structure in an anisotropic environment such as the bacterial cell membrane. To envisage the role of the proline residue located in the middle of the peptide chain on biological activity and secondary structure, we prepared several melectin analogues in which the Pro11 residue was either replaced by other amino acid residues or was omitted. The results of biological testing suggest that a Pro kink in the alpha-helical structure of melectin plays an important role in selectivity for bacterial cells. In addition, a series of N- and C-terminal-shortened analogues was synthesized to examine which region of the peptide is related to antimicrobial activity.
- MeSH
- antibakteriální látky farmakologie chemická syntéza izolace a purifikace MeSH
- cirkulární dichroismus MeSH
- degranulace buněk účinky léků MeSH
- erytrocyty účinky léků MeSH
- gramnegativní bakterie účinky léků MeSH
- grampozitivní bakterie účinky léků MeSH
- hemolýza účinky léků MeSH
- hydrofobní a hydrofilní interakce MeSH
- inhibiční koncentrace 50 MeSH
- kationické antimikrobiální peptidy farmakologie chemická syntéza izolace a purifikace MeSH
- krysa rodu rattus MeSH
- mastocyty fyziologie účinky léků MeSH
- mikrobiální testy citlivosti MeSH
- molekulární sekvence - údaje MeSH
- potkani Wistar MeSH
- sekundární struktura proteinů MeSH
- sekvence aminokyselin MeSH
- spektrometrie hmotnostní - ionizace laserem za účasti matrice MeSH
- včelí jedy chemie MeSH
- včely MeSH
- vysokoúčinná kapalinová chromatografie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- zvířata MeSH
- Publikační typ
- práce podpořená grantem MeSH
Unusual fatty acids with 24, 26, and 28 carbon atoms were found in triacylglycerols (TAGs) isolated from fat body tissue of bumblebee Bombus pratorum. The most abundant one was (Z,Z)-9,19-hexacosadienoic acid. Its structure was determined by mass spectrometry after derivatization with dimethyl disulfide and by infrared spectroscopy. ECL (equivalent chain length) values of its methyl ester were determined on both DB-1 and DB-WAX capillary columns. (Z,Z)-9,19-Hexacosadienoic acid is quite rare in nature. So far it has been identified only in marine sponges, and this work is the first evidence of its occurrence in a terrestrial organism. HPLC/MS analysis of the bumblebee TAGs showed that (Z,Z)-9,19-hexacosadienoic acid is present in one third of all TAG molecular species. As it was found in all sn-TAG positions, it is likely that (Z,Z)-9,19-hexacosadienoic acid is transported to tissues. Interestingly, labial gland secretion of B. pratorum was found to contain (Z,Z)-7,17-pentacosadiene, a hydrocarbon with markedly similar double bond positions and geometry. Possible biosynthetic relationships between these two compounds are discussed.
- MeSH
- chromatografie plynová MeSH
- esterifikace MeSH
- financování organizované MeSH
- hmotnostní spektrometrie MeSH
- hnízdění MeSH
- mastné kyseliny metabolismus MeSH
- triglyceridy metabolismus MeSH
- tukové těleso metabolismus MeSH
- včely metabolismus MeSH
- vysokoúčinná kapalinová chromatografie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- MeSH
- financování organizované MeSH
- Publikační typ
- abstrakty MeSH
