Preparation and Insecticidal Activity of Sea Anemone Peptide AP-GI from Aiptasia pallida

[Objectives] This study was conducted to synthesize sea anemone peptide Ap-GI and investigate its insecticidal activity. [Methods] The linear peptide Ap-GI was synthesized by solid phase peptide synthesis(SPPS), and the linear peptide was subjected to the two-step oxidative folding, mass spectrometry identification and high performance liquid chromatography(HPLC) purification. Then, the MTT method and insect injection method were used to study its insecticidal activity. [Results] The synthesized sea anemone peptide had a purity of 95%. The test results of the MTT method showed that the peptide Ap-GI had the activity of inhibiting the growth of insect cells sf9 with the median effective dose of 0.7 nM;and the test results of the injection method on yellow mealworms showed that the peptide Ap-GI had high insecticidal activity, and the median lethal dose was 16.9 nM. [Conclusions] The sea anemone peptide Ap-GI from Aiptasia pallida has a good inhibitory effect on the growth of insect cells and high-efficiency insecticidal activity, which can lay a foundation for the development of new, safe and efficient peptide biological insecticides.

Studies on Extraction and Activity of Peptides from Haemadipsa hainana

[Objectives]Peptides was extracted from Haemadipsa hainana and its activity was studied.[Methods]Electric stimulation,water extraction and ultrasonic extraction were used to extract the peptides from H.hainana.Then the protein content and molecular weight distribution of H.hainana peptides were detected by the BCA method and SDS-PAGE method,respectively.The antithrombin activity and analgesic activity of the three peptide extracts of H.hainana were detected by Markwardt thrombin titration method and mouse hot plate experiment,respectively.[Results]There extraction methods of electric stimulation,water extraction and ultrasonic extraction were used to extract the peptide extract of H.hainana,and the yields were as follows:water extraction>electrical stimulation>ultrasonic extraction.The three peptide extracts from H.hainana had antithrombin activity,and the antithrombin activity was as follows:water extraction>ultrasonic extraction>electrical stimulation.Through the hot plate experiment in mice,it was verified that the three peptide extracts of H.hainana had analgesic activity,and the analgesic activity was water extraction>electric stimulation>ultrasonic extraction.The analgesic activity of high-dose(100 mg/kg)group of H.hainana obtained by water extraction was slightly weaker than that of tramadol.[Conclusions]This study confirmed that the peptide extract of H.hainana had certain antithrombin and analgesic activity,laying a foundation for the subsequent development and application of H.hainana.

Preparation of Sea Anemone Peptide Toxin Ap-TxI and Its Insecticidal Activity

[Objectives]This study was conducted to synthesize sea anemone peptide toxin Ap-TxI and investigate its insecticidal activity. [Methods] The sea anemone linear peptide toxin Ap-TxI was synthesized by the solid-phase peptide synthesis(SPPS), and six cysteines were oxidized to form three disulfide bonds by a three-step directional oxidation method. Then, purification by high performance liquid chromatography(HPLC) and mass spectrometry identification were performed. Finally, the insect cytotoxicity and insecticidal activity of Ap-TxI were studied by the MTT method and insect injection method. [Results] The oxidized peptide Ap-TxI with three disulfide bonds in natural configuration was successfully synthesized by the SPPS method, and its purity was >90% by HPLC analysis. The results of the MTT method showed that Ap-TxI was active on the growth of insect cells sf9, with a half effective dose of 0.2 nM;and the results of the mealworm injection test showed that the polypeptide Ap-TxI had high insecticidal activity with a median lethal dose of 11.7 nM. [Conclusions] The sea anemone peptide toxin Ap-TxI with high insecticidal effect was obtained, laying a foundation for the development of new, efficient and safe biological insecticides.

Research Progress on the Influence of Structural Changes inμ-Conotoxins on Sodium Channel Receptors

The voltage-gated sodium channel(Na v)is widely present in mammals and can generate cell action potentials,which are related to many diseases.Theμ-Conotoxins(μ-CTx)isolated from the venom of cone snails can specifically block the voltage-gated sodium channel;it can be widely used as a necessary probe to distinguish the Na v channel subtypes.In this study,the effects of eightμ-CTx on different Na v channel isoforms were reviewed,and sequence alignment and protein homologous modeling were used to predict their biological activities,and the structure-activity relationship betweenμ-CTx and mutagenesis strategies.

Optimized Three-Stage Strategy of Orderly Management of File Stream in Network Printing Workflow

This paper proposed the optimized three-stage strategy of orderly management of file stream in network printing workflow. In first stage the customer preflight was added to the conventional prepress preflight, which set quick-type, general-type, stable-type and comprehensive-type preflight scheme for customers by investigating the possibility of occurrence of errors of various preflight entries and customer relevancy. Based on four types of preflight schemes, four customer preflight applications were created by using Pitstop Pro and Connector You. Customers can select one of the appropriate applications for quick preflight before delivering to reduce the probability of returning the files back for correction when errors occur in preflight. Second stage is printing enterprise prepress preflight,which proposed the concept of the prepress preflight tolerance. In addition, according to the different requirements of printing technology and quality, this paper established the prepress preflight scheme based on the printing enterprises’ tolerance for preflight error. Third stage is to manage the optimized sorting of prepress file stream. To achieve it, the SPT rule and the 0-1 programming model were adopted, time spend of preflight, printing process and post-press finishing was also taken into account.Moreover, Enfocus Switch software was applied to establish automated network printing workflow and complete the file stream sorting. Finally, the result of simulation analysis of the optimized strategy shows that the optimized three-stage strategy can effectively shorten the file processing time.

High-Throughput Prediction and Design of Novel Conopeptides for Biomedical Research and Development

Cone snail venoms have been considered a valuable treasure for international scientists and businessmen, mainly due to theirpharmacological applications in development of marine drugs for treatment of various human diseases. To date, around 800Conus species are recorded, and each of them produces over 1,000 venom peptides (termed as conopeptides or conotoxins).This reflects the high diversity and complexity of cone snails, although most of their venoms are still uncharacterized.Advanced multiomics (such as genomics, transcriptomics, and proteomics) approaches have been recently developed to minediverse Conus venom samples, with the main aim to predict and identify potentially interesting conopeptides in an efficientway. Some bioinformatics techniques have been applied to predict and design novel conopeptide sequences, related targets, andtheir binding modes. This review provides an overview of current knowledge on the high diversity of conopeptides andmultiomics advances in high-throughput prediction of novel conopeptide sequences, as well as molecular modeling and designof potential drugs based on the predicted or validated interactions between these toxins and their molecular targets.