Kaneloft6795

Glycosomal malate dehydrogenase from Trypanosoma cruzi (tcgMDH) catalyzes the oxidation/reduction of malate/oxaloacetate, a crucial step of the glycolytic process occurring in the glycosome of the human parasite. Inhibition of tcgMDH is considered a druggable trait for the development of trypanocidal drugs. Sequence comparison of MDHs from different organisms revealed a distinct insertion of a prolin rich 9-mer (62-KLPPVPRDP-70) in tcgMDH as compared to other eukaryotic MDHs. Crystal structure of tcgMDH is solved here at 2.6 Å resolution with Rwork/Rfree values of 0.206/0.216. The tcgMDH forms homo-dimer with the solvation free energy (ΔGo) gain of -9.77 kcal/mol. The dimeric form is also confirmed in solution by biochemical assays, chemical-crosslinking and dynamic light scattering. The inserted 9-mer adopts a structure of a solvent accessible loop in the vicinity of NAD+ binding site. The distinct sequence and structural feature of tcgMDH, revealed in the present report, provides an anchor point for the development of inhibitors specific for tcgMDH, possible trypanocidal agents of the future.Transthyretin (TTR) has been proved to repress neovascularization in diabetic retinopathy environment by regulating the molecules in and downstream of the STAT-4/miR-223-3p/FBXW7 signal pathway; however, the details of its direct targets are still not well understood. The interaction between TTR and a target in nucleus of human retinal microvascular endothelial cells (hRECs), heterogeneous nuclear ribonucleoprotein (hnRNP) A2B1, was screened by immunoprecipitation (IP) and mass spectrum (MS), and it was further confirmed by co-immunoprecipitation (co-IP). Regarding ZDOCK analysis using Discovery Studio, the interface and potential binding sites between TTR and hnRNPA2B1 were simulated; mutants were designed in these regions and five soluble ones were recombinantly expressed and prepared; the interaction between TTR and hnRNPA2B1 were disrupted by several mutated residues. In addition, for several mutated TTRs, the inhibition activities against the proliferation, migration and tube formation of hRECs were absent in vitro. IOX1 datasheet Following the disruption of TTR-hnRNPA2B1, the molecules in and downstream of STAT-4/miR-223-3p/FBXW7 signal pathway, including STAT-4, miR-223-3p, FBXW7 p-Akt and Notch1 could not be regulated by TTR mutants; therefore, a TTR-hnRNPA2B1/STAT-4/miR-223-3p/FBXW7 was proposed. In conclusion, this work suggested that TTR should play a physiological role in diabetic environment by the direct binding with hnRNPA2B1, and it provided a theoretical basis for clinical diagnosis, therapy and further application.Recently, the novel coronavirus (SARS-CoV-2), which has spread from China to the world, was declared a global public health emergency, which causes lethal respiratory infections. Acetylation of several proteins plays essential roles in various biological processes, such as viral infections. We reported that the nucleoproteins of influenza virus and Zaire Ebolavirus were acetylated, suggesting that these modifications contributed to the molecular events involved in viral replication. Similar to influenza virus and Ebolavirus, the coronavirus also contains single-stranded RNA, as its viral genome interacts with the nucleocapsid (N) proteins. In this study, we report that SARS-CoV and SARS-CoV-2 N proteins are strongly acetylated by human histone acetyltransferases, P300/CBP-associated factor (PCAF), and general control nonderepressible 5 (GCN5), but not by CREB-binding protein (CBP) in vitro. Liquid chromatography-mass spectrometry analyses identified 2 and 12 acetyl-lysine residues from SARS-CoV and SARS-CoV-2 N proteins, respectively. Particularly in the SARS-CoV-2 N proteins, the acetyl-lysine residues were localized in or close to several functional sites, such as the RNA interaction domains and the M-protein interacting site. These results suggest that acetylation of SARS-CoV-2 N proteins plays crucial roles in their functions.Secreted phospholipase A2s (sPLA2s) are calcium dependent enzymes involved in various biological events such as lipid metabolism and inflammation. We previously identified the second calcium (Ca2) binding site of human sPLA2 Group IIE (hGIIE) by structural study and suggested that Asn21 act as the switch of Ca2 binding to modulate the enzymatic activity, but the detailed Ca2 binding mechanism is still unclear. Combined with enzymatic assay, model analysis and calcium binding affinity data for mutated hGIIE proteins, we herein further demonstrate that the flexibly bound Ca2 is essential for the catalysis of hGIIE, unlike the stable binding of Ca2 in hGIIA that replenishes the calcium in the typical loop during the reaction. The atypical Ca2 binding feature of hGIIE will provide a better understanding on the catalytic mechanism of hGIIE.The Plasmodium falciparum chloroquine resistance transporter (PfCRT) is a phospho-protein with three identified phosphorylation sites (Ser33, Ser411 and Thr416) at its cytosolic N- and C-termini. In this study, we report on the characterization of PfCRT anti-serum and show the presence of three epitope-specific immunoglobulin (IgG) pools (i.e., IgG-P1, P2, and P3), each recognizing a different epitope in PfCRT cytoplasmic C-terminal. IgG-P2 bound the heptapeptide sequence (408NEDSEGE414), including Ser411. The effect of Ser411 phosphorylation on the binding specificity of IgG-P2 was confirmed using heptapeptides and full-length PfCRT with substitutions of Ser411 with aspartic acid (phospho-serine mimic) and alanine residues. Moreover, using purified IgG-P2, we show the presence of PfCRT homodimer that has un-phosphorylated Ser411 and migrates with an apparent molecular mass of 90 kDa on SDS-PAGE. In addition, parasite lysates showed PfCRT to be more phosphorylated at Ser411 in CQ-sensitive (3D7) than CQ-resistant (Dd2-H) strains of P. falciparum. Taken together, the findings of this study suggest a role for Ser411 phosphorylation in PfCRT structure-function.Isoflurane and sevoflurane are volatile anesthetics (VA) widely used in clinical practice to provide general anesthesia. We and others have previously shown that VAs have immunomodulatory effects and may have a significant impact on the progression of disease states. Flagellin is a component of Gram negative bacteria and plays a significant role in the pathophysiology of bacterial pneumonia through its binding to Toll-like Receptor 5 (TLR5). Our results showed that VAs, not an intravenous anesthetic, significantly attenuated the activation of TLR5 and the release of the neutrophil chemoattractant IL-8 from lung epithelial cells. Furthermore, flagellin-induced lung injury was significantly attenuated by VAs by inhibiting neutrophil migration to the bronchoalveolar space. The lungs of cystic fibrosis (CF) patients are highly colonized by Pseudomonas aeruginosa, which causes inflammation. The retrospective study of oxygenation in patients with CF who had received VA versus intravenous anesthesia suggested that VAs might have the protective effect for gas exchange.