[Tissue culture and rapid propagation of Trichosanthes kirilowii].

Objective: To study tissue culture of Trichosanthes kirilowii, and establish the technique of rapid propagation.

Methods: Cluster buds were induced from stem tip and stem with axillary bud, calluses were induced from stems and leaves.

Results: Cluster buds could be induced on both the bud and axillary bud from 2-years-old tuber of Trichosanthes kirilowii with MS medium containing 2 mg/L BA and 0.

Structure of an excitatory insect-specific toxin with an analgesic effect on mammals from the scorpion Buthus martensii Karsch.

BmK IT-AP is an excitatory insect-specific beta-toxin with analgesic effect from the Chinese scorpion Buthus martensii Karsch (BmK) and consists of 72 residues cross-linked by four disulfide bridges. The crystal structure of BmK IT-AP has been determined at a resolution of 2.6 A by molecular replacement.

Structural mechanism governing cis and trans isomeric states and an intramolecular switch for cis/trans isomerization of a non-proline peptide bond observed in crystal structures of scorpion toxins.

Non-proline cis peptide bonds have been observed in numerous protein crystal structures even though the energetic barrier to this conformation is significant and no non-prolyl-cis/trans-isomerase has been identified to date. While some external factors, such as metal binding or co-factor interaction, have been identified that appear to induce cis/trans isomerization of non-proline peptide bonds, the intrinsic structural basis for their existence and the mechanism governing cis/trans isomerization in proteins remains poorly understood. Here, we report the crystal structure of a newly isolated neurotoxin, the scorpion alpha-like toxin Buthus martensii Karsch (BmK) M7, at 1.

Purification, crystallization and initial structural solution of a new alpha-like toxin with cardiac toxicity from scorpion Buthus martensii Karsch.

An alpha-like toxin named BmK M7 active on both mammals and insects has been purified from the venom of scorpion Buthus martensii Karsch (BmK) recently. The electrophysiological experiments showed that M7 can bind to human cardiac Na+-channel and modify its normal properties, hence can be considered as a cardiotoxin. Single crystals of M7 have been obtained by hanging-drop vapor diffusion method using ammonium sulfate as precipitant in Tris-HCl buffer at pH 8.