Tick-Derived Peptide Blocks Potassium Channel TREK-1.

Ticks transmit a variety of pathogens, including rickettsia and viruses, when they feed on blood, afflicting humans and other animals. Bioactive components acting on inflammation, coagulation, and the immune system were reported to facilitate ticks' ability to suck blood and transmit tick-borne diseases. In this study, a novel peptide, IstTx, from an cDNA library was analyzed.

Isolation and structural identification of a potassium ion channel Kv4.1 inhibitor SsTx-P2 from centipede venom.

Objectives: To isolate a potassium ion channel Kv4.1 inhibitor from centipede venom, and to determine its sequence and structure.

Methods: Ion-exchange chromatography and reversed-phase high-performance liquid chromatography were performed to separate and purify peptide components of centipede venom, and their inhibiting effect on Kv4.

Molecular mechanism by which spider-driving peptide potentiates coagulation factors.

Hemostasis is a crucial process that quickly forms clots at injury sites to prevent bleeding and infections. Dysfunctions in this process can lead to hemorrhagic disorders, such as hemophilia and thrombocytopenia purpura. While hemostatic agents are used in clinical treatments, there is still limited knowledge about potentiators targeting coagulation factors.

A Novel Peptide from Promotes Wound Healing in Mice.

Amphibian skin contains wound-healing peptides, antimicrobial peptides, and insulin-releasing peptides, which give their skin a strong regeneration ability to adapt to a complex and harsh living environment. In the current research, a novel wound-healing promoting peptide, PM-7, was identified from the skin secretions of , which has an amino acid sequence of FLNWRRILFLKVVR and shares no structural similarity with any peptides described before. It displays the activity of promoting wound healing in mice.

General mechanism of spider toxin family I acting on sodium channel Nav1.7.

Various peptide toxins in animal venom inhibit voltage-gated sodium ion channel Nav1.7, including Nav-targeting spider toxin (NaSpTx) Family I. Toxins in NaSpTx Family I share a similar structure, i.

Two-pore channel blockade by phosphoinositide kinase inhibitors YM201636 and PI-103 determined by a histidine residue near pore-entrance.

Human two-pore channels (TPCs) are endolysosomal cation channels and play an important role in NAADP-evoked Ca release and endomembrane dynamics. We found that YM201636, a PIKfyve inhibitor, potently inhibits PI(3,5)P-activated human TPC2 with an IC of 0.16 μM.

Centipede KCNQ Inhibitor SsTx Also Targets K1.3.

It was recently discovered that Ssm Spooky Toxin (SsTx) with 53 residues serves as a key killer factor in red-headed centipede's venom arsenal, due to its potent blockage of the widely expressed KCNQ channels to simultaneously and efficiently disrupt cardiovascular, respiratory, muscular, and nervous systems, suggesting that SsTx is a basic compound for centipedes' defense and predation. Here, we show that SsTx also inhibits K1.3 channel, which would amplify the broad-spectrum disruptive effect of blocking K7 channels.

A membrane disrupting toxin from wasp venom underlies the molecular mechanism of tissue damage.

The molecular mechanism of the local hypersensitivity reactions to wasp venom including dermal necrosis remains an enigma regardless of the numerosity of the reported cases. In this study, we discovered a new membrane disrupting toxin, VESCP-M2 responsible for tissue damage symptoms following Vespa mandarinia envenomation. Electrophysiological assays revealed a potent ability of VESCP-M2 to permeate the cell membrane whereas in vivo experiments demonstrated that VESCP-M2 induces edema, pain and dermal necrosis characterized by the presence of morphological and behavioral phenotypes, pro-inflammatory mediators, biomarkers as well as the disruption of dermal tissue.

Purification and Characterization of a Novel Kazal-Type Trypsin Inhibitor from the Leech of Hirudinaria manillensis.

Kazal-type serine proteinase inhibitors are found in a large number of living organisms and play crucial roles in various biological and physiological processes. Although some Kazal-type serine protease inhibitors have been identified in leeches, none has been reported from Hirudinaria manillensis, which is a medically important leech. In this study, a novel Kazal-type trypsin inhibitor was isolated from leech H.

A novel defensin-like antimicrobial peptide from the skin secretions of the tree frog, Theloderma kwangsiensis.

Defensins are one of the major families of antimicrobial peptides (AMPs), and have been reported from prokaryotic to eukaryotic kingdoms. But defensins are seldom found in amphibian which is a major resource of novel AMPs. A novel defensin-like AMP (defensin-TK) was isolated and characterized from skin secretions of the tree frog Theloderma kwangsiensis.

An immunoregulatory peptide from tsetse fly salivary glands of Glossina morsitans morsitans.

Tsetse fly Glossina morsitans morsitans is an important insect vector of African trypanosomes, which cause human African trypanosomiasis (HAT). As other hematophagous arthropods, tsetse fly relies heavily on the pharmacological propriety of their saliva to suppress host's immune reactions and get blood meal. However little information is available on immune regulators from testes fly.

A Novel Trypsin Inhibitor-Like Cysteine-Rich Peptide from the Frog Lepidobatrachus laevis Containing Proteinase-Inhibiting Activity.

Various bio-active substances in amphibian skins play important roles in survival of the amphibians. Many protease inhibitor peptides have been identified from amphibian skins, which are supposed to negatively modulate the activity of proteases to avoid premature degradation or release of skin peptides, or to inhibit extracellular proteases produced by invading bacteria. However, there is no information on the proteinase inhibitors from the frog Lepidobatrachus laevis which is unique in South America.