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Insect phenoloxidase, presented as an inactive precursor prophenoloxidase (PPO) in hemolymph, catalyzes melanin formation, which is involved in wound healing, pathogen killing, reversible oxygen collection during insect respiration, and cuticle and eggshell formation. Mosquitoes possess 9 to 16 PPO members across different genera, a number that is more than that found in other dipteran insects. However, the reasons for the redundancy of these PPOs and whether they have distinct biochemical properties and physiological functions remain unclear. Phylogenetic analysis confirmed that Aedes aegypti PPO6 (Aea-PPO6) is an ortholog to PPOs in other insect species, classified as the classical insect type, while other Aea-PPOs are unique to Diptera, herein referred to as the dipteran type here. We characterized two Aea-PPO members, Aea-PPO6, the classical insect type, and Aea-PPO10, a dipteran type, which exhibit distinct substrate specificities. By resolving Aea-PPO6's crystal structure and creating a chimera protein (Aea-PPO6-cm) with Motif 1 ( 217 GDGPDSVVR 225 ) from Aea-PPO10, we identified the motif that determines PPO substrate specificity. In vivo, loss of Aea-PPO6 led to larval lethality, while Aea-PPO10 was involved in development, pigmentation, and immunity. Our results enhance the understanding of the functional diversification of mosquito PPOs., Competing Interests: Competing interests statement:The authors declare no competing interest.

Glioma is the most common and aggressive primary brain tumor in adults with high morbidity and mortality. Rapid proliferation and diffuse migration are the main obstacles to successful glioma treatment. Xanthatin, a sesquiterpene lactone purified from Xanthium strumarium L., possesses a significant antitumor role in several malignant tumors. In this study, we report that xanthatin suppressed glioma cells proliferation and induced apoptosis in a time- and concentration-dependent manner, and was accompanied by autophagy inhibition displaying a significantly reduced LC3 punctate fluorescence and LC3II/I ratio, decreased level of Beclin 1, while increased accumulation of p62. Notably, treating glioma cells with xanthatin resulted in obvious activation of the PI3K-Akt-mTOR signaling pathway, as indicated by increased mTOR and Akt phosphorylation, decreased ULK1 phosphorylation, which is important in modulating autophagy. Furthermore, xanthatin-mediated pro-apoptosis in glioma cells was significantly reversed by autophagy inducers (rapamycin or Torin1), or PI3K-mTOR inhibitor NVP-BEZ235. Taken together, these findings indicate that anti-proliferation and pro-apoptosis effects of xanthatin in glioma are most likely by inhibiting autophagy via activation of PI3K-Akt-mTOR pathway, suggesting a potential therapeutic strategy against glioma., (© 2022 The Authors. Pharmacology Research & Perspectives published by British Pharmacological Society and American Society for Pharmacology and Experimental Therapeutics and John Wiley & Sons Ltd.)

Three new crystal structures containing [PtCl₆] 2− , pyridinium and benzimidazole groups have been prepared: [PtCl₆]·(H-bzm)₂·2(H₂O) ( 1 ), [PtCl₆]·(H-bipy)₂·2(H₂O) ( 2 ), [PtCl₆]·(H-dimethyl-bipy)₂·2(H₂O) ( 3 ) [H-bzm: benzimidazole cation, H-bipy: 2,2′-bipyridine cation, H-dimethyl-bipy: 4,4′-bimethyl-2,2′-bipyridine cation]. All compounds have been fully characterized by elemental analyses, single-crystal X-ray analyses, IR spectra, TG analyses, and fluorescence studies. Single-crystal X-ray diffraction analysis suggests that the primary synthon contains ⁺N⁻H···Cl − , including ionic bonding and hydrogen bonding interactions. The dimensions are enhanced further by secondary O⁻H ∙∙Cl and N⁻H ∙∙O hydrogen bonding interactions between donor and acceptor atoms located at the periphery of these synthons. Moreover, coulombic attractions between the ions play an important role in reinforcing the structures of these complexes. In addition, antitumor activity against human lung adenocarcinoma cell line (A549) and human nasopharyngeal carcinoma cell line (CNE-2) was performed. These complexes all showed inhibition to the two cell lines, while complex 3 exhibited higher efficiency than complexes 1 ⁻ 2 .

Methanotrophs could degrade methane and various chlorinated hydrocarbons. The analysis on methane monooxygenase gene cluster sequence would help to understand its catalytic mechanism and enhance the application in pollutants biodegradation. The methanotrophs was enriched and isolated with methane as the sole carbon source in the nitrate mineral salt medium. Then, five chlorinated hydrocarbons were selected as cometabolic substrates to study the biodegradation. The phylogenetic tree of 16S rDNA using MEGE5.05 software was constructed to identify the methanotroph strain. The pmoCAB gene cluster encoding particulate methane monooxygenase (pMMO) was amplified by semi-nested PCR in segments. ExPASy was performed to analyze theoretical molecular weight of the three pMMO subunits. As a result, a strain of methanotroph was isolated. The phylogenetic analysis indicated that the strain belongs to a species of Methylocystis, and it was named as Methylocystis sp. JTC3. The degradation rate of trichloroethylene (TCE) reached 93.79% when its initial concentration was 15.64 μmol/L after 5 days. We obtained the pmoCAB gene cluster of 3 227 bp including pmoC gene of 771 bp, pmoA gene of 759 bp, pmoB gene of 1 260 bp and two noncoding sequences in the middle by semi-nested PCR, T-A cloning and sequencing. The theoretical molecular weight of their corresponding gamma, beta and alpha subunit were 29.1 kDa, 28.6 kDa and 45.6 kDa respectively analyzed using ExPASy tool. The pmoCAB gene cluster of JTC3 was highly identical with that of Methylocystis sp. strain M analyzed by Blast, and pmoA sequences is more conservative than pmoC and pmoB. Finally, Methylocystis sp. JTC3 could degrade TCE efficiently. And the detailed analysis of pmoCAB from Methylocystis sp. JTC3 laid a solid foundation to further study its active sites features and its selectivity to chlorinated hydrocarbon.