Data on first record of brown morph banded langur (presbytis femoralis), leucistic dusky leaf monkey ( trachypithecus obscurus ) in Malaysia and review of morph diversity in langur (colobinae)

Morphism refer to polymorphic species, in which multiple colour variants coexist within a population. Morphism in pri- mates is common and langurs also exhibit certain character- istics of morphism, such as conspicuous natal coats. Banded langurs ( Presbytis femoralis ) and dusky leaf monkey ( Trachyp- ithecus obscurus ) exhibits the same characteristics of conspic- uous natal coats, but these coats are only limited to infants and changed when they reached adulthood. This article re- ports the first discovery of rare brown morph of two adult male banded langurs and one leucistic adult female dusky leaf monkey in Malaysia. We also conducted a systematic literature search to review the diversity of morphism in leaf monkey globally

Data on First Record of Brown Morph Banded Langur (Presbytis femoralis), Leucistic Dusky Leaf Monkey (Trachypithecus obscurus) in Malaysia and Review of Morph Diversity in Langur (Colobinae)

Morphism refer to polymorphic species, in which multiple colour variants coexist within a population. Morphism in primates is common and langurs also exhibit certain characteristics of morphism, such as conspicuous natal coats. Banded langurs (Presbytis femoralis) and dusky leaf monkey (Trachypithecus obscurus) exhibits the same characteristics of conspicuous natal coats, but these coats are only limited to infants and changed when they reached adulthood. This article reports the first discovery of rare brown morph of two adult male banded langurs and one leucistic adult female dusky leaf monkey in Malaysia

La famille Kunitz/BPTI des venins de serpents: Structure, classification et potentiel pharmacologique

International audienceSnake venoms are rich sources of serine proteinase inhibitors that are members of the Kunitz/BPTI (bovine pancreatic trypsin inhibitor) family. Generally, these inhibitors are formed by 60 amino acids approximately. Their folding is characterised by a canonical loop that binds in a complementary manner to the active site of serine protease. Some variants from snake venoms show only weak inhibitory activity against proteases while others are neurotoxic. Moreover, proteases inhibitors are involved in various physiological processes, such as blood coagulation, fibrinolysis, and inflammation. Also, these molecules showed an anti-tumoral potent and anti-metastatic effect. Interestingly, Kunitz/BPTI peptides can have exquisite binding specificities and possess high potency for their targets making them excellent therapeutic candidates.Les venins des serpents sont riches en inhibiteurs de sérine protéases qui sont membres de la famille Kunitz / BPTI (inhibiteur de la trypsine pancréatique bovine). Ces inhibiteurs sont en général formés par environ 60 acides aminés. Leur modèle structural est caractérisé par la présence d’une boucle canonique qui se lie d’une manière complémentaire au site actif des sérines protéases. Certains inhibiteurs ne montrent qu'une faible activité inhibitrice contre la protéase tandis que d'autres sont neurotoxiques. De plus, ces peptides sont impliqués dans de divers processus physiologiques, tels que la coagulation sanguine, la fibrinolyse et l'inflammation. En outre, ces molécules ont montré un puissant effet anti-tumoral et anti-métastatique. Ainsi, les inhibiteurs de type Kunitz/BPTI peuvent avoir des spécificités de liaison et possèdent un potentiel élevé envers leurs cibles qui les rend d'excellents candidats thérapeutiques

Influence of a dispersion of magnetic and nonmagnetic nanoparticles on the magnetic Fredericksz transition of the liquid crystal 5CB

A long time ago, Brochard and de Gennes predicted the possibility of significantly decreasing the critical magnetic field of the Fredericksz transition (the magnetic Fredericksz threshold) in a mixture of nematic liquid crystals and ferromagnetic particles, the so-called ferronematics. This phenomenon is rarely measured to be large, due to soft homeotropic anchoring induced at the nanoparticle surface. Here we present an optical study of the magnetic Fredericksz transition combined with a light scattering study of the classical nematic liquid crystal: the pentylcyanobiphenyl (5CB), doped with 6 nm diameter magnetic and nonmagnetic nanoparticles. Surprisingly, for both nanoparticles, we observe at room temperature a net decrease of the threshold field of the Fredericksz transition at low nanoparticle concentrations, which appears associated with a coating of the nanoparticles by a brush of polydimethylsiloxane copolymer chains inducing planar anchoring of the director on the nanoparticle surface. Moreover, the magnetic Fredericksz threshold exhibits nonmonotonic behavior as a function of the nanoparticle concentration for both types of nanoparticles, first decreasing down to a value from 23% to 31% below that of pure 5CB, then increasing with a further increase of nanoparticle concentration. This is interpreted as an aggregation starting at around 0.02 weight fraction that consumes more isolated nanoparticles than those introduced when the concentration is increased above c = 0.05 weight fraction (volume fraction 3.5 × 10 −2). This shows the larger effect of isolated nanoparticles on the threshold with respect to aggregates. From dynamic light scattering measurements we deduced that, if the decrease of the magnetic threshold when the nanoparticle concentration increases is similar for both kinds of nanoparticles, the origin of this decrease is different for magnetic and nonmagnetic nanoparticles. For nonmagnetic nanoparticles, the behavior may be associated with a decrease of the elastic constant due to weak planar anchoring. For magnetic nanoparticles there are non-negligible local magnetic interactions between liquid crystal molecules and magnetic nanoparticles, leading to an increase of the average order parameter. This magnetic interaction thus favors an easier liquid crystal director rotation in the presence of external magnetic field, able to reorient the magnetic moments of the nanoparticles along with the molecules

Targeting α1 inserted domain (I) of α1β1 integrin by Lebetin 2 from M. lebetina transmediterranea venom decreased tumorigenesis and angiogenesis.

International audienceThrough the recent development of knowledge in biotechnology and bioinformatics, snake venoms are widely used to develop new drugs to treat diseases such as hypertension and cancer. We have previously reported that Lebetin 2 isolated from Macrovipera lebetina transmediterranea venom displays a potent anti-platelet activity and exerts a cardioprotective effect in ischemia-reperfusion (IR) injury model. Here, we report that Lebetin 2 possess an anti-tumor effect by targeting the integrin receptor function. It was thus able to inhibit both adhesion and migration of pheochromocytoma cells (PC12) and α1β1 integrin-expressing CHO cells (CHO-α1) to type I and IV collagens. Moreover, this peptide affects proliferation of PC12 cells by modulating AKT phosphorylation. Furthermore, Lebetin 2 exhibits a potent anti-angiogenic effect as assessed in vitro and ex vivo, using both the embryo chick chorioallantoic membrane model (CAM) and rat aortic ring assay. Interestingly, the interaction mode of Lebetin 2 with the integrin α1β1, assessed in silico, showed that the peptide represents a steric obstruction preventing the collagen from enforcing the interactions with the integrin

PIVL, a new serine protease inhibitor from Macrovipera lebetina transmediterranea venom, impairs motility of human glioblastoma cells.

International audienceA novel Kunitz-type serine proteinase inhibitor, termed PIVL, was purified to homogeneity from the venom of the Tunisian snake Macrovipera lebetina transmediterranea. It is a monomeric polypeptide chain cross-linked by three disulfide linkages with an isotope-averaged molecular mass of 7691.7 Da. The 67-residue full-length PIVL sequence was deduced from a venom gland cDNA clone. Structurally, PIVL is built by a single Kunitz/BPTI-like domain. Functionally, it is able to specifically inhibit trypsin activity. Interestingly, PIVL exhibits an anti-tumor effect and displays integrin inhibitory activity without being cytotoxic. Here we show that PIVL is able to dose-dependently inhibit the adhesion, migration and invasion of human glioblastoma U87 cells. Our results also show that PIVL impairs the function of αvβ3 and to a lesser extent, the activity of αvβ6, αvβ5, α1β1 and α5β1 integrins. Interestingly, we demonstrate that the (41)RGN(43) motif of PIVL is likely responsible for its anti-cancer effect. By using time lapse videomicroscopy, we found that PIVL significantly reduced U87 cells motility and affected cell directionality persistence by 68%. These findings reveal novel pharmacological effects for a Kunitz-type serine proteinase inhibitor

AaTX1, from Androctonus australis scorpion venom: Purification, synthesis and characterization in dopaminergic neurons

International audienceWe have purified the AaTX1 peptide from the Androctonus australis (Aa) scorpion venom, previously cloned and sequenced by Legros and collaborators in a venom gland cDNA library from Aa scorpion. AaTX1 belongs to the alpha-Ktx15 scorpion toxins family (alpha KTx15-4). Characterized members of this family share high sequence similarity and were found to block preferentially I-A-type voltage-dependent K+ currents in rat cerebellum granular cells in an irreversible way. In the current work, we studied the effects of native AaTX1 (nAaTX1) using whole-cell patch-clamp recordings of I-A current in substantia nigra pars compacta dopaminergic neurons. At 250 nM, AaTX1 induces 90% decrease in I-A current amplitude. Its activity was found to be comparable to that of rAmmTX3 (alpha KTx15-3), which differs by only one conserved (R/K) amino acid in the 19th position suggesting that the difference between R19 and K19 in AaFX1 and AmmTX3, respectively, may not be critical for the toxins' effects. Molecular docking of both toxins with Kv4.3 channel is in agreement with experimental data and suggests the implication of the functional dyade K27-Y36 in toxin-channel interactions. Since AaTX1 is not highly abundant in Aa venom, it was synthesized as well as AmmTX3. Synthetic peptides, native AaTX1 and rAmmTX3 peptides showed qualitatively the same pharmacological activity. Overall, these data identify a new biologically active toxin that belongs to a family of peptides active on Kv4.3 channel. (C) 2014 Elsevier Ltd. All rights reserved