Structures And Functions Of The Peptide Toxins From The Spider Chilobrachys Jingzhao And A Non-peptide Toxin From The Spider Ornithoctonus Huwena

The spider Chilobrachys jingzhao was recently identified as a new specice. The crude venom contains a mixture of compounds with different types of biological activities. Two novel Peptide Neueotoxins were purified from the venom of Chilobrachys jingzhao by using combination of ion-exchange and reverse phase HPLC. The complete amino acid sequences of them were obtained by automated Edman degradation,and the biological functions of them have been investigated on several experimental models.They are named as JZTX-â…¡ and JZTX-â…¢, respectively. The masses of the two toxins are determined by the MALDTI-TOF MS as 3726. 35Daand 3918. 46Da, respectively.The sequences of the two toxins are determined and found to consist of 34 and 36 amino acid residues, respectively.Both of the two sequences include six Cys residues, which form three disulphide bonds. JZTX-â…¡ can block neuromuscular transmission in an isolated mouse phrenic nerve diaphragm . JZTX- â…¡ show 63% identity with SNX-482 toxin,a neurotoxin isolated from the spider Hysterocrates gigas. Based on high sequence identity with SNX-482, it was estimated that JZTX-â…¡ could also block the E-type calcium channel just like SNX-482, which is accepted as a blocker of E-type calcium channel. JZTX-â…¢ could block the sodium channel hHl(Navl.5) which was expressioned in the Xenopus occytes.The Chinese bird spider Ornithoctonus huwena is distributed in the hilly areas of Yunan and Guangxi in the south of China. So far several neurotoxins have been isolated from the venom of spider Ornithoctonus huwena. A novel low molecular compound which was effective to heart is isolated from the venom of the spider through two times reverse phase High performance liquid chromatography.Its exact molecular weight is 147Da determined byESI mass spectrum. According to its MS, NMR, IR, the toxin has been proved as apoloyamine amides. The compound showed effects on isolated atria, although the structure of this compound is different from the Ach, the bioactivities of them are similar to each other.