Spawning period of Mediterranean marine fishes

We collected all available information (i.e. international and local journals, conference proceedings, theses, technical reports) on the spawning season (n = 511 stocks, 168 species), gonadosomatic index (n = 237 stocks, 81 species) and sex ratio (n = 97 stocks, 68 species) of Mediterranean marine fish. The 511 stocks represented 20 orders (most were Perciformes, 283 stocks) and 65 families (most were Sparidae: 17 species and 63 stocks). Overall, 346 stocks (128 species) spawned between April and August, 139 stocks (60 species) between September and March, while the remaining 26 stocks (13 species) were all-year-round spawners. In addition, 174 stocks (34.1%) were characterised by an extended (>4 months) spawning season, but, for most stocks (332 stocks, 64.4%), spawning duration ranged from 2 to 4 months inclusive. Regardless of the onset and the duration of spawning, the spawning period of 284 and 287 stocks included June and July, respectively, indicating that most Mediterranean species are summer spawners. Female gonadosomatic index ranged between 0.06 and 37 (mean ± SE = 8.55 ± 0.647, n = 95) and was significantly higher (t-test: t = 5.58, P < 0.001) than the corresponding male one, which ranged between 0.06 and 30 (mean ± SE = 4.21 ± 0.431, n = 95). Congeneric species that occupied the same area and share the same requirements exhibited successive and non-overlapping spawning (e.g. Sparidae in the Adriatic Sea, Mugilidae in the Ionian Sea and Tunisian waters). The knowledge of the spawning period coupled with information on spawning and nursery grounds and detailed knowledge of mating systems, social interactions, maturity and fecundity may be very useful for fisheries management.     

Enantioselective biocatalytic synthesis of (S)-monastrol

The first enantioselective biocatalytic synthesis of (S)-monastrol has been developed via an unexpected and unusual enzymatic pathway as suitable route. Whereas attempts for a direct hydrolysis of racemic monastrol were not successful, formation of racemic O-butanoyl monastrol and subsequent enantioselective hydrolysis furnished O-butanoyl (S)-monastrol with 97% ee. Cleavage of the O-butanoyl moiety then gave the desired (S)-monastrol with 96% ee.     

Novel insights into the calcium action in cherry fruit development revealed by high-throughput mapping

Plant Molecular Biology - This work provides the first system-wide datasets concerning metabolic changes in calcium-treated fruits, which reveal that exogenously applied calcium may specifically...     

Quantitative structure activity relationships (QSAR) of substituded (S)-phenylpiperidines as preferential dopamine autoreceptor antagonists

A QSAR analysis for substituted (S)-phenylpiperidines as dopamine (DA) antagonists is described. The studied derivatives differ at the nitrogen substitutent (R) and at the substitutents (X) of the phenyl-ring. The analysis was done using the C-QSAR suite program (Biobyte) through the Internet. Clog P, CMR, M_Vol, B₁ and L (the Verloop's sterimol parameters for the substitutents) were used as parameters. In all the three studied cases clog P plays a significant part in the QSAR of DA antagonists, followed by the steric factors. In one case the electronic effect contributes significantly.     

Synthesis of 13C-labeled and functionalized Hyaluronan derivatives for biophysical studies and surface modifications

A convergent synthesis of a tetrasaccharide partial sequence of ¹³C-labeled Hyaluronan is presented. This tetrasaccharide can be used for biophysical studies as well as for surface modifications. Furthermore, tetrasaccharide 7 can be employed for the synthesis of additionally labeled higher oligomers of Hyaluronan on the basis of the presented methodology.     

Cis-trans isomerization of the Epstein-Barr virus determinant peptide EENLLDFVRF after the DM1 TCR recognition of the HLA-B*4405/peptide complex

The Epstein–Barr virus determinant peptide EENLLDFVRF shows high immunogenicity when presented by HLA-B*4405 allotype. This fact is accompanied by a cis–trans isomerization of the Leu5-Asp6 peptide bond upon TCR binding of the pMHC complex. Molecular dynamics simulations of pMHC/TCR structures, with the EENLLDFVRF peptide in cis and trans conformations have been employed in order to examine the structure and dynamics of the pMHC complex with such an unusual conformation. The results, based on MM-PBSA free energy computations as well as buried surface area analysis and interactions at the pMHC/TCR interface, indicate that the TCR binds preferably the pMHC complex with the Leu5-Asp6 peptide bond in cis conformation. It is the first time that this notable conformational feature of T-cell epitope is investigated.     

Nck1 and Grb2 localization patterns can distinguish invadopodia from podosomes

Invadopodia are matrix-degrading ventral cell surface structures formed in invasive carcinoma cells. Podosomes are matrix-degrading structures formed in normal cell types including macrophages, endothelial cells, and smooth muscle cells that are believed to be related to invadopodia in function. Both invadopodia and podosomes are enriched in proteins that regulate actin polymerization including proteins involved in N-WASp/WASp-dependent Arp2/3-complex activation. However, it is unclear whether invadopodia and podosomes use distinct mediators for N-WASp/WASp-dependent Arp2/3-complex activation. We investigated the localization patterns of the upstream N-WASp/WASp activators Nck1 and Grb2 in invadopodia of metastatic mammary carcinoma cells, podosomes formed in macrophages, and degradative structures formed in Src-transformed fibroblasts and PMA-stimulated endothelial cells. We provide evidence that Nck1 specifically localizes to invadopodia, but not to podosomes formed in macrophages or degradative structures formed in Src-transformed fibroblasts and PMA-stimulated endothelial cells. In contrast, Grb2 specifically localizes to degradative structures formed in Src-transformed fibroblasts and PMA-stimulated endothelial cells, but not invadopodia or podosomes formed in macrophages. These findings suggest that distinct upstream activators are responsible for N-WASp/WASp activation in invadopodia and podosomes, and that all these ventral cell surface degradative structures have distinguishing molecular as well as structural characteristics. These patterns of Nck1 and Grb2 localization, identified in our study, can be used to sub-classify ventral cell surface degradative structures.     

Insights into the structure of the LC13 TCR/HLA-B8-EBV peptide complex with molecular dynamics simulations

One key step in the immune response against infected or tumor cells is the recognition of the T-cell receptor (TCR) by class I major histocompatibility complexes. The complex between the HLA-B8 molecule and the immunodominant peptide with sequence FLRGRAYGL, derived from the Epstein-Barr virus, with the LC13 TCR has been determined by X-ray diffraction. The complex has been used as a starting point in a molecular dynamics study in order to investigate the dynamics of the complex association and to explore the specific interactions of the complex formation. The analyzed structures provided evidence that the peptide adopts an open type β-turn conformation close to C-terminal part, which dominates peptide/TCR interactions. Conformational energy landscape analysis indicated the presence of two conformational clusters in the peptide’s structure, underlying the backbone flexibility of the peptide despite being surrounded by two receptors. The peptide/MHC/TCR interface was found to hold significant number of solvent molecules, more specifically the peptide has been found to have approximately seventeen hydrogen bonds with water molecules. The molecular dynamics simulation indicated the disruption of some MHC/TCR contacts, mainly with the CDR1α loop. However, several other interactions emerged that resulted in a stable association during the 20 ns trajectory, as revealed by the buried surface area analysis.