Comprehensive comparison of two protein family of P-ATPases (13A1 and 13A3) in insects

A SARS-CoV-2 -human metalloproteome interaction map

The recent pandemic caused by the novel coronavirus resulted in the greatest global health crisis since the Spanish flu pandemic of 1918. There is limited knowledge of whether SARS-CoV-2 is physically associated with human metalloproteins. Recently, high-confidence, experimentally supported protein-protein interactions between SARS-CoV-2 and human proteins were reported. In this work, 58 metalloproteins among these human targets have been identified by a structure-based approach. This study reveals that most human metalloproteins interact with the recently discovered SARS-CoV-2 orf8 protein, whose antibodies are one of the principal markers of SARS-CoV-2 infections. Furthermore, this work provides sufficient evidence to conclude that Zn²⁺ plays an important role in the interplay between the novel coronavirus and humans. First, the content of Zn-binding proteins in the involved human metalloproteome is significantly higher than that of the other metal ions. Second, a molecular linkage between the identified human Zn-binding proteome with underlying medical conditions, that might increase the risk of severe illness from the SARS-CoV-2 virus, has been found. Likely perturbations of host cellular metal homeostasis by SARS-CoV-2 infection are highlighted.

Cloning, expression, and bioinformatics analysis and characterization of a β-galactosidase from Bacillus coagulans T242

The activities of β-galactosidases from bacteria and molds are affected by temperature, pH, and other factors in the processing of dairy products, limiting their application, so it is necessary to find alternative lactases. In this study, the β-galactosidase gene from Bacillus coagulans T242 was cloned, co-expressed with a molecular chaperone in Escherichia coli BL21, and subjected to bioinformatic and kinetic analyses and lactase characterization. The results show that the enzyme is a novel thermostable neutral lactase with optimum hydrolytic activity at pH 6.8 and 50°C. The thermal stability and increased lactose hydrolysis activity of β-galactosidase in the presence of Ca²⁺ indicated its potential application in the dairy industry.

Gene synthesizing, expression and immunogenicity characterization of recombinant translation elongation factor 2 from Dermatophagoides farinae

House dust mite (HDM) hypersensitivity increasingly affects millions of individuals worldwide. Although numerous major allergens produced by HDM species have been characterized, some of the less potent allergens remain to be studied. The present study aimed to obtain the recombinant allergen of Translation Elongation Factor 2 (TEF 2) from the HDM Dermatophagoides farinae by synthesizing, and then expressing the recombinant TEF 2 to identify its immunogenicity. In the present study, the D. farinae TEF 2 (Der f TEF 2) was synthesized, expressed and purified. The molecular characteristics of Der f TEF 2 were analyzed using bioinformatics approaches. The recombinant protein was purified via affinity chromatography, and the allergenicity was assessed using immunoblotting, ELISAs and skin prick tests. The gene for TEF 2 consists of 2,535 bp and encodes an 844‑amino acid protein. A positive response to recombinant Der f TEF 2 was detected in 16.2% of 37 patients with HDM allergies using skin prick tests. In addition, the immunoblotting indicated that the protein showed a high ability to bind serum IgE from patients allergic to HDMs, and that the recombinant TEF 2 was highly immunogenic. Bioinformatics analysis predicted 17 peptides as B cell epitopes (amino acids 29‑35, 55‑64, 92‑99, 173‑200, 259‑272, 311‑318, 360‑365, 388‑395, 422‑428, 496‑502, 512‑518, 567‑572, 580‑586, 602‑617, 785‑790, 811‑817 and 827‑836) and 14 peptides as T cell epitopes (amino acids 1‑15, 65‑79, 120‑134, 144‑159, 236‑250, 275‑289, 404‑418, 426‑440, 463‑477, 510‑524, 644‑658, 684‑698, 716‑730 and 816‑830). The software DNAStar predicted the secondary structure of TEF 2, and showed that 27 α‑helices and five β‑sheets were found in the protein. In conclusion, the present study cloned and expressed the Der f TEF 2 gene, and the recombinant protein exhibited immunogenicity, providing a theoretical bases, and references, for the diagnosis and treatment of allergic disease.