Multiple Mutations on α, β and γ Domains of Streptokinase Lead to the Generation of Highly Efficient Cysteine Analogues with Promising Features.

Background: Streptokinase, one of the most widely used thrombolytic medicines, is a favorable protein for site-specific PEGylation as it lacks any cysteine residues in its amino acid sequence; however, any changes in the protein's structure should be carefully planned to avoid undesired changes in its function.

Objectives: This study aimed to design and produce novel di/tri-cysteine variants of streptokinase from previously developed cysteine analogues, Arg45, Glu263, and Arg319, as candidates for multiple site-specific PEGylation.

Methods: Using bioinformatics tools and site-directed mutagenesis, we incorporated concurrent mutations at Arg45, Glu263, and Arg319 (carried out in our previous study) to create di/tri-cysteine variants of streptokinase proteins (SK, SK, and SK) and evaluated their kinetic activity parameters by a colorimetric method, using H-D-Val-Leu-Lys-pNA.

OdTx12/GNA, a chimeric variant of a β excitatory toxin from Odontobuthus doriae, reveals oral toxicity towards Locusta migratoria and Tenebrio molitor.

OdTx12, a beta excitatory toxin from Odontobothus doriae had previously been identified and characterized. It had been shown that OdTx12 causes significant lethal effects on insects by injection but does not show any toxicity on mice. Due to the natural ineffectiveness of scorpion toxins to act as oral toxins, OdTx12 was fused to Galanthus nivalis agglutinin (GNA), a protein with the potential to cross the insect gut.

Cloning and expression of OdTx12, a β excitatory toxin from Odontobuthus doriae, in Escherichia coli and evaluation of its bioactivity in Locusta migratoria.

The venom of Odontobuthus doriae contains several peptide toxins that interfere with the sodium channel function of cell membranes, some of which specifically act on the insect's sodium channel without affecting mammalian cells. In this study sodium channel toxins of Odontobuthus doriae were aligned to other closely related toxins by BLAST and ClustalW servers. Among these toxins, NaTx12 (OdTx12) showed more than 90% similarity to the most known beta excitatory toxin, AaHIT1; furthermore, our modeling studies confirmed high tertiary structure similarity of these proteins.

Molecular Characterization of Mosquitoes (Diptera: Culicidae) in Northwestern Iran by Using rDNA-ITS2.

Several mosquito species are vectors of disease; however, to understand their role in disease transmission, accurate species identification is of particular importance. Morphological identification is the main method used, but molecular techniques have emerged as a tool for the identification of closely related species. In this study, mosquitoes from the West Azerbaijan Province in northwestern Iran were characterized on the basis of their rDNA-ITS2 sequences.

Fauna and Larval Habitats of Mosquitoes (Diptera: Culicidae) of West Azerbaijan Province, Northwestern Iran.

Background: Several important diseases are transmitted by mosquitoes. Despite of the potential of the occurrence of some mosquito-borne diseases such as West Nile, dirofilariasis and malaria in the region, there is no recent study of mosquitoes in West Azerbaijan Province. The aim of this investigation was to study the fauna, composition and distribution of mosquitoes and the characteristics of their larval habitats in this province.