Detecting inconsistency in biological molecular databases using ontologies

The rapid growth of life science databases demands the fusion of knowledge from heterogeneous databases to answer complex biological questions. The discrepancies in nomenclature, various schemas and incompatible formats of biological databases, however, result in a significant lack of interoperability among databases. Therefore, data preparation is a key prerequisite for biological database mining. Integrating diverse biological molecular databases is an essential action to cope with the heterogeneity of biological databases and guarantee efficient data mining. However, the inconsistency in biological databases is a key issue for data integration. This paper proposes a framework to detect the inconsistency in biological databases using ontologies. A numeric estimate is provided to measure the inconsistency and identify those biological databases that are appropriate for further mining applications. This aids in enhancing the quality of databases and guaranteeing accurate and efficient mining of biological databases.

A helical conotoxin from Conus imperialis has a novel cysteine framework and defines a new superfamily

Cone snail venoms are a rich source of peptides, many of which are potent and selective modulators of ion channels and receptors. Here we report the isolation and characterization of two novel conotoxins from the venom of Conus imperialis. These two toxins contain a novel cysteine framework, C-C-C-CC-C, which has not been found in other conotoxins described to date. We name it framework XXIII and designate the two toxins im23a and im23b; cDNAs of these toxins exhibit a novel signal peptide sequence, which defines a new K-superfamily. The disulfide connectivity of im23a has been mapped by chemical mapping of partially reduced intermediates and by NMR structure calculations, both of which establish a I-II, III-IV, V-VI pattern of disulfide bridges. This pattern was also confirmed by synthesis of im23a with orthogonal protection of individual cysteine residues. The solution structure of im23a reveals that im23a adopts a novel helical hairpin fold. A cluster of acidic residues on the surface of the molecule is able to bind calcium. The biological activity of the native and recombinant peptides was tested by injection into mice intracranially and intravenously to assess the effects on the central and peripheral nervous systems, respectively. Intracranial injection of im23a or im23b into mice induced excitatory symptoms; however, the biological target of these new toxins has yet to be identified.