Cloning and identification of a new multifunctional Ascaris-type peptide from the hemolymph of Buthus martensii Karsch.

Only a few work have been done for peptides from non-venom gland tissues of venomous animals. Here, with the help of the whole body transcriptomic and the hemolymph proteomic data of the Chinese scorpion Buthus martensii Karsch, we identified the first Ascaris-type peptide BmHDP from scorpion hemolymph. The precursor of BmHDP has 80 residues, including a 16 residue signal peptide and a 64 residue mature peptide. The mature peptide has 10 conserved cysteines and adopts a conserved Ascaris-type fold. Using combined inclusion body refolding and biochemical identification strategies, recombinant BmHDP was obtained successfully. Protease inhibitory assays showed that BmHDP inhibited chymotrypsin apparently at a concentration of 8 nM. Patch-clamp experiments showed that BmHDP inhibited the Kv1.3 potassium channel apparently at a concentration of 1000 nM. Coagulation experiment assays showed that BmHDP inhibited intrinsic coagulation pathway apparently at a concentration of 500 nM. To the best of our knowledge, BmHDP is the first Ascaris-type peptide from scorpion hemolymph. Our work highlighted a functional link between scorpion non-venom gland peptides and venom gland toxin peptides, and suggested that scorpion hemolymph might be a new source of bioactive peptides.

A novel protein with anti-metastasis activity on 4T1 carcinoma from medicinal fungus Cordyceps militaris.

Cordyceps militaris is a famous fungus used in traditional Chinese medicine for nearly one thousand years. And its fruiting body is known to possess anticancer and immunomodulatory activities. This study describes the isolation, characterization, and test of antitumor activity of a C. militaris protein, called here as "C. militaris immunoregulatory protein" (CMIP). CMIP was purified through a three-step chromatographic procedure. The MS analyses showed that CMIP corresponded to an uncharacterized protein (CCM_01955) in the C. militaris transcriptional database. Circular dichroism of CMIP revealed the composition of 35.5% ß-sheet, 18.5% α-helix, 17.0% turn and 29.0% random coil. No significant cytotoxicity of CMIP was observed on HeLa, HepG2 and 4T1 tumor cells. However, CMIP demonstrated anti-metastasis activity on a mouse model of 4T1 breast cancer lung metastasis. It reduced the number of tumor nodules in the lung of tumor-bearing mice and prolonged their survival time. Furthermore, proliferation of the 4T1 cells was inhibited by macrophage-CMIP conditioned media. And the mRNA levels of cytokines TNF-α, IL-1ß and IL-6 were increased significantly in peritoneal macrophages treated by CMIP. These results reveal the antitumor potential of CMIP, thus reinforcing the importance of biochemical prospecting of C. militaris.