Excitation-contraction coupling was characterized in scorpion striated muscle fibers using standard microelectrode techniques as employed in studies on vertebrate skeletal muscle. The action potential of scorpion muscle consists of two phases of regenerative activity. A relatively fast, overshooting initial spike is followed by a prolonged after-discharge of smaller, repetitive spikes. This aft...

Predators feeding on toxic prey may evolve physiological resistance to the preys' toxins. Grasshopper mice (Onychomys spp.) are voracious predators of scorpions in North American deserts. Two species of grasshopper mice (Onychomys torridus and Onychomys arenicola) are broadly sympatric with two species of potentially lethal bark scorpion (Centruroides exilicauda and Centruroides vittatus) in th...

Voltage sensing by voltage-gated sodium channels determines the electrical excitability of cells, but the molecular mechanism is unknown. ß-scorpion toxins bind specifically to neurotoxin receptor site 4 and induce a negative shift in the voltage dependence of activation through a voltagesensor trapping mechanism. Kinetic analysis showed that β-scorpion toxin binds to the resting state and subs...

scorpion bite is a common health problem in many parts of the world, including the iran’s tropics. there are thousands of cases and a number of deaths due to scorpion bite every year in the country. the present study aims to provide further data regarding the details, complications and outcomes of scorpion bite cases referring to razi hospital, ahwaz, from march 2011 to april 2012. a total of 2...

SUMMARY Two web-based applications to analyze amino acids three-dimensional (3D) local environment within protein structures-SCORPION and FORMIGA-are presented. SCORPION and FORMIGA produce a graphical presentation for simple statistical data showing the frequency of residue occurrence within a given sphere (defined here as the 3D contacts). The center of that sphere is placed at the Calpha and...

Kurtoxin is a 63-amino acid polypeptide isolated from the venom of the South African scorpion Parabuthus transvaalicus. It is the first and only peptide ligand known to interact with Cav3 (T-type) voltage-gated Ca(2+) channels with high affinity and to modify the voltage-dependent gating of these channels. Here we describe the nuclear magnetic resonance (NMR) solution structure of kurtoxin dete...

Scorpions and their venoms have been employed in medication since thousands of years in Asia. The scorpion venom is an extremely advanced mixture of salts, nucleotides, biogenic amines, enzymes, mucoproteins, peptides and proteins (e.g. Neurotoxins). Scorpion venoms contain peptides that block or modify ion-channel function and present some doable applications to regulate cell excitability. Spe...

Despite scorpions being locally abundant in many parts of Australia, scorpion sting is a poorly defined clinical condition in Australia. Many health-care workers are unaware of the effects of their stings and scorpions are often feared based on their international reputation. Five scorpion stings that occurred in different parts of Australia where the scorpion was caught at the time of the stin...

The resistance of the scorpion Androctonus australis to its own venom, as well as to the venom of other species, was investigated. A comparison of the electrical and pharmacological properties of muscle and nerve fibres from Androctonus australis with those from the crayfish Procambarus clarkii enabled us to understand the lack of effect of scorpion venom (110-180 microg ml-1) and purified toxi...