Identification and Characterization of Novel Proteins from Arizona Bark Scorpion Venom That Inhibit Nav1.8, a Voltage-Gated Sodium Channel Regulator of Pain Signaling.

The voltage-gated sodium channel Nav1.8 is linked to neuropathic and inflammatory pain, highlighting the potential to serve as a drug target. However, the biophysical mechanisms that regulate Nav1.

Isolation and characterization of CvIV4: a pain inducing α-scorpion toxin.

Background: Among scorpion species, the Buthidae produce the most deadly and painful venoms. However, little is known regarding the venom components that cause pain and their mechanism of action. Using a paw-licking assay (Mus musculus), this study compared the pain-inducing capabilities of venoms from two species of New World scorpion (Centruroides vittatus, C.

Development of JNK2-selective peptide inhibitors that inhibit breast cancer cell migration.

Despite their lack of selectivity toward c-Jun N-terminal kinase (JNK) isoforms, peptides derived from the JIP (JNK Interacting Protein) scaffolds linked to the cell-penetrating peptide TAT are widely used to investigate JNK-mediated signaling events. To engineer an isoform-selective peptide inhibitor, several JIP-based peptide sequences were designed and tested. A JIP sequence connected through a flexible linker to either the N-terminus of an inverted TAT sequence (JIP(10)-Δ-TAT(i)) or to a poly arginine sequence (JIP(10)-Δ-R(9)) enabled the potent inhibition of JNK2 (IC(50) ≈ 90 nM) and exhibited 10-fold selectivity for JNK2 over JNK1 and JNK3.

Unique biomaterial compositions direct bone marrow stem cells into specific chondrocytic phenotypes corresponding to the various zones of articular cartilage.

Numerous studies have reported generation of cartilage-like tissue from chondrocytes and stem cells, using pellet cultures, bioreactors and various biomaterials, especially hydrogels. However, one of the primary unsolved challenges in the field has been the inability to produce tissue that mimics the highly organized zonal architecture of articular cartilage; specifically its spatially varying mechanical properties and extra-cellular matrix (ECM) composition. Here we show that different combinations of synthetic and natural biopolymers create unique niches that can "direct" a single marrow stem cell (MSC) population to differentiate into the superficial, transitional, or deep zones of articular cartilage.

Comparison of radioimmunoassay and liquid chromatography tandem mass spectrometry for determination of juvenile hormone titers.

This paper compares the results of juvenile hormone (JH) titer determinations in two insect species, Melanoplus sanguinipes, a migratory grasshopper, and Acyrthosiphon pisum, the pea aphid, using a chiral-specific JH radioimmunoassay (RIA) and liquid chromatography tandem mass spectrometry (LC-MS/MS), after extraction of JH with either hexane or isooctane-methanol. We compared results of JH titer determinations done on extracts of M. sanguinipes hemolymph taken from animals flown to exhaustion in tethered flight tests or unflown controls and from whole body extracts of A.

Clostridium taeniosporum spore ribbon-like appendage structure, composition and genes.

Clostridium taeniosporum spores have about 12 large, flat, ribbon-like appendages attached through a common trunk at one spore pole to a previously unknown surface layer outside the coat that is proposed to be called the 'encasement'. Appendages are about 4.5 microm long, 0.

Relationship of adipokinetic hormone I and II to migratory propensity in the grasshopper, Melanoplus sanguinipes.

This report examines three aspects of adipokinetic hormone (AKH) involvement in migratory flight behavior in the grasshopper, Melanoplus sanguinipes. The titer of hemolymph AKH I during long-duration tethered flight was examined using radioimmunoassay (RIA) after narrow bore RP-HPLC. The hemolymph fraction containing AKH I was assayed using commercially available anti-Tyr1-AKH I serum.

Discovery and characterization of Melanoplus sanguinipes AKH II by combined HPLC and mass spectrometry methods.

Reversed-phase high-performance liquid chromatography (RP-HPLC) allows for fractionation of extract from the corpora cardiaca of insects for examination of bioactivity or immunoreactivity and/or subsequent characterization of the peptides. Using RP-HPLC, we have previously identified an adipokinetic hormone (AKH) from the corpora cardiaca of the migratory grasshopper Melanoplus sanguinipes. This hydrophobic decapeptide has the same primary structure as locust (Locusta migratoria; Lom) AKH I.