Identification and characterisation of novel wasp mastoparans and chemotactic peptides from the venom of social wasp Polistes stigma (Hymenoptera: Vespidae: Polistinae).

Polistes stigma is a common social wasp found in continental Southeast Asia. Despite its wide distribution and abundance, hitherto, there are no studies on small or medium molecular weight components of the venom. For the first time, this study has described the amino acid sequences and its post-translation modifications (PTM's) of four wasp-mastoparans (Ps 1524, Ps 1540, Ps 1556 and Ps 1630), three chemotactic peptides (Ps1417, Ps1434 and Ps1474) and one more (Ps1549) lysine rich peptide from the venom of P. stigma. There were 27 mass traces obtained from the crude natural venom, in which the complete amino acid sequences of 8 peptides were solved. Further, single disulphide bonded peptides uncommon in wasp venoms were identified. The mastoparan peptides were rich in hydrophobic residues. In addition, the peptides Ps1549, Ps1630, Ps1434 and Ps1417 were found to have unusual PTM's of C-terminal amidation. This preliminary study comprehends the untapped compounds present in wasp venom that are equally valuable to widely studied venoms of snakes, spiders and cone snails.

Diversity of Conopeptides and Conoenzymes from the Venom Duct of the Marine Cone Snail Conus bayani as Determined from Transcriptomic and Proteomic Analyses.

Marine cone snails are predatory gastropods characterized by a well-developed venom apparatus and highly evolved hunting strategies that utilize toxins to paralyze prey and defend against predators. The venom of each species of cone snail has a large number of pharmacologically active peptides known as conopeptides or conotoxins that are usually unique in each species. Nevertheless, venoms of only very few species have been characterized so far by transcriptomic approaches. In this study, we used transcriptome sequencing technologies and mass spectrometric methods to describe the diversity of venom components expressed by a worm-hunting species, Conus bayani. A total of 82 conotoxin sequences were retrieved from transcriptomic data that contain 54 validated conotoxin sequences clustered into 21 gene superfamilies including divergent gene family, 17 sequences clustered to 6 different conotoxin classes, and 11 conotoxins classified as unassigned gene family. Seven new conotoxin sequences showed unusual cysteine patterns. We were also able to identify 19 peptide sequences using mass spectrometry that completely overlapped with the conotoxin sequences obtained from transcriptome analysis. Importantly, herein we document the presence of 16 proteins that include five post-translational modifying enzymes obtained from transcriptomic data. Our results revealed diverse and novel conopeptides of an unexplored species that could be used extensively in biomedical research due to their therapeutic potentials.

A novel approach to predict chlorophyll-a in coastal-marine ecosystems using multiple linear regression and principal component scores.

Chlorophyll-a is an established indexing marker for phytoplankton abundance and biomass amongst primary food producers in an aquatic ecosystem. Understanding and modeling the level of Chlorophyll-a as a function of environmental parameters have been found to be very beneficial for the management of the coastal ecosystems. This study developed a mathematical model to predict Chlorophyll-a concentrations based on a data driven modeling approach. The prediction model was developed using principal component analysis (PCA) and multiple linear regression analysis (MLR) approaches. The predictive success (R2) of the model was found to be ~84.8% for first approach and ~83.8% for the second approach. A final model was generated using a combined principal component scores (PCS) and MLR approach that involves fewer parameters and has a predictive ability of 83.6%. The PCS-MLR method helped to identify the relationship amongst dependent as well as predictor variables and eliminated collinearity problems. The final model is quite simple and intuitive and can be used to understand real system operations.

Seawater quality conditions of the south Andaman Sea (Bay of Bengal, Indian Ocean) in lustrum during 2010s decade.

Andaman and Nicobar islands is one of the major tourism hubs of the World. Most travelers visit these islands for historical attractions, beaches, snorkeling, scuba diving, coral reefs, adventure and recreation. Port Blair is the capital and sole entry/exit point of these islands. The coasts of Port Blair Bay (PBB) and Wandoor Creek (WC) are largely populated due to its services offered to different public/private sectors and for the economic significance. Nevertheless, the global recognition of these islands relies on its healthy ecosystem. Effective management of beaches, bays and their environmental services requires knowledge of coastal water quality. This study assesses the datasets of twenty seawater quality parameters of PBB and WC generated during five years (2011-2015) at eight sites. Multivariate statistical techniques were used for (i) analysis and interpretation of water quality parameters (ii) identification of pollution factors/sources and (iii) understanding spatio-temporal variations valuable for coastal water quality management.

Identification of short single disulfide-containing contryphans from the venom of cone snails using de novo mass spectrometry-based sequencing methods.

We identified 12 short single disulfide-containing conopeptides from the venom of Conus coronatus, C. leopardus, C. lividus and C. zonatus. Interestingly, we detected the shortest contryphan sequence thus far characterized which contains only six amino acid residues. We also identified three distinct contryphan sequences of C. lividus without any proline residues and one sequence with an unusual post-translational modification (bromination of tryptophan). Furthermore, we characterized venom peptides of C. zonatus for the first time.

Contryphan Genes and Mature Peptides in the Venom of Nine Cone Snail Species by Transcriptomic and Mass Spectrometric Analysis.

The occurrence of contryphans, a class of single-disulfide-bond-containing peptides, is demonstrated by the analysis of the venom of nine species of cone snails. Ten full gene sequences and two partial gene sequences coding for contryphan precursor proteins have been identified by next-generation sequencing and compared with available sequences. The occurrence of mature peptides in isolated venom has been demonstrated by LC-ESI-MS/MS analysis. De novo sequencing of reduced, alkylated contryphans from C. frigidus and C. araneosus provides evidence of sequence variation and post-translational modification, notably gamma carboxylation of glutamic acid. The characterization of Fr965 (C. frigidus) provides a rare example of a sequence lacking Pro at position 5 in the disulfide loop. The widespread occurrence of contryphan genes and mature peptides in the venom of diverse cone snails is suggestive of their potential biological significance.

A sleep-inducing peptide from the venom of the Indian cone snail Conus araneosus.

The marine snail Conus araneosus has unusual significance due to its confined distribution to coastal regions of southeast India and Sri Lanka. Due to its relative scarceness, this species has been poorly studied. In this work, we characterized the venom of C. araneosus to identify new venom peptides. We identified 14 novel compounds. We determined amino acid sequences from chemically-modified and unmodified crude venom using liquid chromatography-electrospray ionization mass spectrometry and matrix assisted laser desorption ionization time-of-flight mass spectrometry. Ten sequences showed six Cys residues arranged in a pattern that is most commonly associated with the M-superfamily of conotoxins. Four other sequences had four Cys residues in a pattern that is most commonly associated with the T-superfamily of conotoxins. The post-translationally modified residue (pyroglutamate) was determined at the N-terminus of two sequences, ar3h and ar3i respectively. In addition, two sequences, ar3g and ar3h were C-terminally amidated. At a dose of 2 nmol, peptide ar3j elicited sleep when injected intraperitoneally into mice. To our knowledge, this is the first report of a peptide from a molluscivorous cone snail with sleep-inducing effects in mice. The novel peptides characterized herein extend the repertoire of unique peptides derived from cone snails and may add value to the therapeutic promise of conotoxins.