Protein and Peptide Letters最新文献

Background: Revealing the process and mechanism of colorectal cancer will facilitate the discovery of new biomarkers and contribute to the development of targeted drugs.

Objectives: This study aimed to explore the potentially functional circRNA-miRNA-mRNA network in colorectal cancer (CRC), and further explore its mechanism.

Methods: Bioinformatics analysis was used to identify the differentially expressed circRNAs and mRNAs. Gene set enrichment analysis and KEGG pathways analysis were used to screen out the differentially expressed genes and observe crucial pathways that might have a strong association with CRC. Then, a network targeting circRNA, miRNA, and mRNA has been built by using the Cytoscape software. In addition, the expression of circRNA_0001573, miR-382-5p, and FZD3 was detected by qRT-PCR in CRC tissues and cells (SW480, HCT116, and HT29).

Results: Abnormal expressions of circRNAs and mRNAs were obtained by bioinformatics analysis and visualized by Volcano plot and Heatmap. A series of highly correlated pathways were enriched by KEGG analysis. The interaction network of circRNA_0001573/miR-382-5p/FZD3 axis was predicted. The expressions of circRNA_0001573 and FZD3 were highly upregulated and the miR- 382-5p expression level was decreased in CRC tissues and cell lines (SW480, HCT116, and HT29).

Conclusion: Our study suggests that circRNA_0001573 and circRNA_0001573/miR-382-5p/FZD3 regulatory networks might provide a potential diagnosis for colorectal cancer.

Papillary thyroid carcinoma (PTC) is a common endocrine malignant tumor. The incidence of PTC has increased in the past decades and presents a younger trend. Accumulating evidence indicates that circular RNAs (circRNAs), featured with non-linear, closed-loop structures, play pivotal roles in tumorigenesis and regulate cell biological processes, such as proliferation, migration, and invasion, by acting as microRNA (miRNA) sponges. Additionally, due to their unique stability, circRNAs hold promising potential as diagnostic biomarkers and effective therapeutic targets for PTC treatment. In this review, we systematically arrange the expression level of circRNAs, related clinical characteristics, circRNA-miRNA-mRNA regulatory network, and molecular mechanisms. Furthermore, related signaling pathways and their potential ability of diagnostic biomarkers and therapeutic targets are discussed, which might provide a new strategy for PTC diagnosis, monitoring, and prognosis.

Cholesterol was first found in gallstones as an animal sterol; hence it is called cholesterol. Cholesterol oxidase is the chief enzyme in the process of cholesterol degradation. Its role is obtained by the coenzyme FAD, which catalyzes the isomerization and oxidation of cholesterol to produce cholesteric 4-ene-3-ketone and hydrogen peroxide at the same time. Recently, a great advance has been made in the discovery of the structure and function of cholesterol oxidase, and it has proven added value in clinical discovery, medical care, food and biopesticides development and other conditions. By recombinant DNA technology, we can insert the gene in the heterologous host. Heterologous expression (HE) is a successful methodology to produce enzymes for function studies and manufacturing applications, where Escherichia coli has been extensively used as a heterologous host because of its economical cultivation, rapid growth, and efficiency in offering exogenous genes. Heterologous expression of cholesterol oxidase has been considered for several microbial sources, such as Rhodococcus equi, Brevibacterium sp., Rhodococcus sp., Streptomyces coelicolor, Burkholderia cepacia ST-200, Chromobacterium, and Streptomyces spp. All related publications of numerous researchers and scholars were searched in ScienceDirect, Scopus, PubMed, and Google Scholar. In this article, the present situation and promotion of heterologous expression of cholesterol oxidase, the role of protease, and the perspective of its possible applications were reviewed.

Background: Several reports have indicated that ultrasonication can change the solubility of muscle proteins and improves the functional properties of meat and isolated muscle proteins. Moreover, available literature suggests that ultrasonication can significantly improve the gelling properties of muscle proteins.

Objectives: The present study was carried out to investigate the effect of low-frequency ultrasonication on the secondary structure of myosin and the impact of these structural changes on solubility and gelling ability.

Methods: Myosin from breast muscles (Pectoralis major) of broiler chicken was extracted and exposed to low-frequency ultrasonication for 30 min. Four aliquots collected at the interval of 5, 10, 20, and 30 min were analysed for change in ATPase activity, sulfhydryl content, surface hydrophobicity, alpha-helicity. The possible impact of these changes on heat-induced gelation was observed through electron micrographs.

Results: Ultrasonication reduced the enzymatic activity of myosin and increased the reactive sulfhydryl content. Decreased α-helicity and increased intrinsic fluorescence displayed significant structural changes at the secondary and tertiary levels. Myosin aggregation, as indicated by electron micrographs, showed a marked decrease. The microstructure of myosin gels displayed a distinct correlation with ultrasonication-induced structural changes. Furthermore, improved microstructure led to a significant increase in the water retention capacity of myosin gels.

Conclusion: In conclusion, ultrasonication of myosin caused a marked change in structure at the tertiary and secondary levels. Structural changes apparently confined within the globular head region and rod portion of myosin were displayed by reduced enzymatic activity and improved gelation/solubility. Results of our study convincingly showed that ultrasonication improved the microstructure of myosin gels resulting in increased WHC.

Introduction: A complex study of the antioxidant system enzymes (AOS) is an important subject of biochemical research; changes in the activity of these enzymes can be used as a biochemical marker of various processes in plants. At the same time, practically little attention has been paid to describing the regularities of these enzymatic reactions in different wood formation processes, such as xylogenesis. This article discusses the outcomes of different behaviors of AOS enzymes, which are involved in both the redistribution of the ROS balance and phenolic compounds at the early stages of wood formation in young plants of silver birch (Betula pendula Roth) with straight-grained wood and Karelian birch (Betula pendula Roth var. carelica (Merckl.) Hamet-Ahti) with non-figured and figured parts within the single trunk.

Background: Spectrophotometric determination of AOS enzymes' activity can be used as a biochemical marker in the different wood formation processes, including xylogenesis. In this study, we studied structural anomalies of the woody plant trunk of Karelian birch (Betula pendula Roth var. carelica (Merckl.) Hamet- Ahti).

Objective: This study aimed to study AOS enzymes' activity in 12-year-old plants of silver birch (Betula pendula Roth) with straight-grained wood and Karelian birch (Betula pendula Roth var. carelica (Merckl.) Hamet-Ahti) with non-figured and figured parts within the single trunk.

Methods: Plant tissues were ground in liquid nitrogen to a uniform mass and homogenized at 4°C in the buffer containing 50 mM HEPES (pH 7.5), 1 mM EDTA, 1 mM EGTA, 3 mM DTT, 5 mM MgCl2, and 0.5 mM PMSF. After 20 min extraction, the homogenate was centrifuged at 10000 g for 20 min (MPW-351R, Poland). The sediment was washed in the buffer thrice. The pooled supernatant and sediment were dialyzed at 4°C for 18-20 h against a tenfold diluted homogenization buffer. The enzymes' activity was determined spectrophotometrically (Spectrophotometer SF-2000, OKB Spectr, Russia). Proteins in the extracts were quantified by the method of Bradford.

Results: We observed different behaviors of the studied enzymes involved in both the redistribution of the ROS balance and phenolic compounds with subsequent lignification even at the early stages of wood formation in young plants and even in different trunk parts within a tree, which was consistent with results obtained earlier on adult plants. High SOD activity in the phloem compared to the activity in the xylem was accompanied by higher CAT activity. The POD/SOD ratio was significantly higher in the figured trunk parts in Karelian birch compared to other variants in the xylem and higher in Karelian birch plants compared to plants of common birch in the phloem. The CAT/POD ratio was significantly higher in plants with no signs of anomalies. The high POD and PPO

Introduction: Catechol o-methyltransferase plays a key role in the metabolism of catecholamine neurotransmitters. At present, its catalytic mechanism, overall structure, and kinetic characteristics have been basically clarified, but few people have paid attention to the function of solvents on enzymatic methyl transfer reactions. The influence of solvents on enzymatic reactions has always been a fuzzy hot topic. In addition, as a well-studied typical methyltransferase, COMT is a good test bed for exploring the source of the solvent isotope effect, which is a powerful tool in enzymatic mechanism research.

Methods: We have measured the kinetic parameters of methyl transfer catalyzed by COMT in both normal water (H₂O) and heavy water (D₂O) by high-performance liquid chromatography (HPLC) in the range of pL 6 ~ 11.

Results: The kinetic characteristics of COMT in H₂O and D₂O were significantly different under different pH/pD conditions. Significant solvent kinetic isotope effects (SKIE) were obtained, especially inverse solvent kinetic isotope effects (SKIE < 1) were observed in this methyl transfer reaction for the first time.

Conclusion: Traditional factors which could interpret the solvent isotope effect were ruled out. It's suggested that the solvent might affect the overall conformation as well as the flexibility of protein through non-covalent forces, thus altering the catalytic activity of COMT and leading to the solvent isotope effect.

Monkeypox is a zoonosis that re-emerged in 2022, generating cases in non-endemic countries for the disease and creating a public health issue. The rapid increase in the number of cases kindles a need for quick, inexpensive diagnostic tests for the epidemiological control of the disease. The high cost of molecular tests can make this control more difficult to access in poorer regions, with immunological tests being a more viable option. In this mini-review, a search was conducted in the main databases for peptide and protein options that could be used in the development of serological diagnostic tests. Nine viable registres were found, and seven were selected (two patents and five studies). The main studies used the B21R peptide sequence as it is a high immunogenic epitope. In addition, studies on the improvement of these sequences were also found to avoid cross-reactions against other viruses of the same family, proposing a rational approach using multiepitope recombinant proteins. These approaches demonstrated high sensitivity and specificity values and are seen as viable options for developing new tests. New effective serological testing options, when combined with awareness, disease surveillance, early diagnosis, and rapid communication, form a set of key strategies used by health systems to control the spread of the monkeypox virus.

Designing effective diagnostics, biotherapeutics, and biocatalysts are a few interesting potential outcomes of protein engineering. Despite being just a few decades old, the discipline of de novo protein designing has provided a foundation for remarkable outcomes in the pharmaceuticals and enzyme industries. The technologies that will have the biggest impact on current protein therapeutics include engineered natural protein variants, Fc fusion protein, and antibody engineering. Furthermore, designing protein scaffolds can be used in developing next-generation antibodies and in transplanting active sites in the enzyme. The article highlights the important tools and techniques used in protein engineering and their application in the engineering of enzymes and therapeutic proteins. This review further sheds light on the engineering of superoxide dismutase, an enzyme responsible for catalyzing the conversion of superoxide radicals to oxygen and hydrogen peroxide by catalyzing a redox reaction at the metal center while concurrently oxidizing and reducing superoxide free radicals.

Background: Hepatocellular carcinoma is a primary liver cancer and 6th most common cancer globally. Inefficient diagnostic strategies and the limited availability of treatments are the foremost reasons. Variable factors directly impact the disease burden, among them, molecular alterations have been found to play a significant role. In liver, argininosuccinate synthase-1 is a center of arginine metabolism and rate limiting enzyme of urea cycle. It also triggers multiple mechanisms that lead to HCC pathogenesis.

Objectives: The aim of this study is to analyze the ASS1 gene expression, its polymorphic genotype and microsatellite instability among HCC patients from our Pakistani population.

Method: Blood samples were collected from disease and healthy control individuals. Allele-Specific PCR was performed for SNP analysis. MSI of tri and tetra nucleotide repeats were analyzed by PCR. The differential expression of ASS1 gene was also investigated. Furthermore, the reactome database and STRING software were utilized for finding correlations between ASS1 gene with other associated gene/proteins.

Results: The GG wild-type genotype was more prevailed in the disease group as compared to the control. Significant downregulation in ASS1 and NOS2 genes was observed. Bioinformatics analysis reveals the correlation between ASS1 polymorphism and HCC development appears to be linked with the EMT pathway and polyamine production. Furthermore, MSI significantly resided in the disease group. Results were analyzed statistically to calculate the significance of obtained results.

Conclusion: Study concludes that the insight of HCC mechanism through population-specific genetic mutations and altered gene expression of ASS1 might be helpful in early diagnostic and therapeutic purposes.

Background: Polypeptides that comprise less than 100 amino acids (50 amino acids in some cases) are referred to as small proteins (SPs), however, as of date, there is no strict definition. In contrast to the small polypeptides that arise due to proteolytic activity or abrupt protein synthesis, SPs are coded by small open reading frames (sORFs) and are conventionally synthesized by ribosomes.

Purpose of the review: Although proteins that contain more than 100 amino acids have been studied exquisitely, studies on small proteins have been largely ignored, basically due to the unsuccessful detection of these SPs by traditional methodologies/techniques. Serendipitous observation of several small proteins and elucidation of their vital functions in cellular processes opened the floodgate of a new area of research on the new family of proteins called "Small proteins". Having known the significance of such SPs, several advanced techniques are being developed to precisely identify and characterize them.

Conclusion: Bacterial small proteins (BSPs) are being intensely investigated in recent days and that has brought the versatile role of BSPs into the limelight. In particular, identification of the fact that BSPs exhibit antimicrobial activity has further expanded its scope in the area of therapeutics. Since the microbiome plays an inevitable role in determining the outcome of personalized medicine, studies on the secretory small proteins of the microbiome are gaining momentum. This review discusses the importance of bacterial small proteins and peptides in terms of their therapeutic applications.