The Protein Journal最新文献

Thioredoxin-like ferredoxin is a small homodimeric protein containing a [2Fe-2S] cluster in each monomer. It is only found in bacteria but its physiological function remains largely unknown. The cobalamin biosynthetic operon in the genome of the purple phototroph Rhodobacter capsulatus encodes a putative ferredoxin dubbed as CfrX. To characterize this protein, we cloned, expressed, purified, and crystalized the recombinant CfrX in the iron-sulfur cluster-bound state, and solved the structure at 2.1-Å resolution. Adopting a typical thioredoxin-like ferredoxin fold, a CfrX monomer binds one [2Fe-2S] cluster through four Cys residues located on two protruding loops. Unexpectedly, CfrX dimerizes in a previously unreported manner. With the structural information, we ascertained CfrX as a thioredoxin-like ferredoxin. While the precise function of CfrX in cobalamin biosynthesis is elusive, a link between CfrX and aerobic cobaltochelatase should exist due to the gene clustering pattern. We also discussed the possible relationship among CfrX, CobW, and CobNST with respect to the [2Fe-2S] cluster.

In this study, we identified and partially purified antimicrobial peptides belonging to the family of lipid transfer proteins (LTPs) from Capsicum chinense seeds (UENF 1751 accession). Fractions rich in LTPs were obtained via ion exchange chromatography and subsequently purified via reverse-phase chromatography in an HPLC system. Therefore, two fractions were revealed: C1 (the nonretained fraction) and C2 (the retained fraction in ion-exchange chromatography). Fraction C1 was subjected to reverse-phase chromatography via a C18 column on an HPLC system, and ten fractions were obtained (P1–P10), all of which significantly inhibited the growth of Candida albicans, except for P4 and P9. The viability analysis of the active fractions at a concentration of 100 µg.mL^-1 against C. albicans revealed that they did not exhibit fungicidal activity but rather exhibited fungistatic activity. The peptide is considered fungicidal when it results in the total loss of viable yeast cells, that is, when it causes the complete death of the fungi. When the substance only inhibits cell growth, but does not eliminate them completely, the effect is classified as fungistatic. Fractions P3, P4, P7, and P10 inhibited Tenebrio molitor larvae α-amylase. The P10 fraction presented protein bands in its electrophoretic profile with a molecular mass between 6.5 kDa and 14.2 kDa and reacted positively to an antibody produced against a protein from the LTP family bywestern blotting. The results of the analysis of amino acid residues from the P10 fraction revealed similarity between type I LTPs and type II LTPs. The ultrastructural aspects of C. albicans cells exposed to the P10 fraction were evaluated via transmission electron microscopy (TEM), with significant differences in their morphology being evident compared with those of the control. In summary, our results demonstrated the presence of LTPs in C. chinense seeds with inhibitory effects on the growth of yeasts of the genus Candida, which exhibited fungistatic effects and structural changes in C. albicans cells, in addition to exhibiting inhibitory effects on the larval insect T. molitor α-amylase.

The crucial involvement of the Fat Mass and Obesity-associated (FTO) protein in both metabolic and non-metabolic diseases has been documented since its discovery. This enzyme, known as FTO, is a demethylase that belongs to the 2-oxoglutarate-dependent nucleic acid demethylases. Its primary function is to target N6-methyladenosine (m⁶A) in RNA, which is crucial in regulating RNA stability, processing, and expression. This review facilitates understanding the FTO gene variations linked to Body Mass Index (BMI) and obesity, resulting in increased vulnerability to type 2 diabetes. While prior reviews have already discussed the link between FTO and BMI and its impact on type 2 diabetes, the current review additionally examines the emerging evidence suggesting a direct influence of the FTO gene on metabolism. Additionally, the paper discusses the alternative role of FTO and emphasizes the endophenotypes in neurological circuits and the demethylase function of FTO in neurodegenerative disorders. The review further examines the impact of FTO on several physiological systems and emphasizes the need to study FTO as a potential multitarget for future research and therapies.

Bee venom is secreted by a gland in the abdominal cavity of bees. The venom, especially that of honeybees, contains certain enzymes and peptides that, when administered in high doses, are effective against various diseases. Peptides such as melittin and phospholipase A₂ can target various cancer cells. In this study, we investigated the antiproliferative effects of administering low-dose bee venom in K-562 chronic myeloid leukaemia cells. Our proteomic study revealed regional variation of the content of bee venom and high levels of melittin, apamin and secapin, as well as phospholipase A₂ and hyaluronidase. In addition, eight new, previously unidentified proteins were identified. The effects of bee venom on cell viability and drug–cell interaction were investigated at 24, 48 and 72 h. According to the MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide) results, the bee venom decreased K-562 cell viability dose-dependently at all time points. Cell viability decreased 48 and 72 h after bee venom administration but increased in the control group left untreated for 72 h. The inhibition percentages for the highest bee venom concentration (0.4 µM) at 24, 48 and 72 h were 55%, 80% and 92%, respectively. The cell–drug interactions indicated that the cell surfaces, which were smooth and clear before drug application, gradually deteriorated and started to shrink after the application. In conclusion, at increasing doses, bee venom was found to have a strong antiproliferative effect in K-562 chronic myeloid leukaemia cell lines.

Considering the limited treatment options for acute lung injury (ALI) and pulmonary fibrosis (PF), ozone treatment may be promising as a new immunological agent with its ability to modulate cytokines and interferons. We aimed to investigate the effects of inhaled ozone therapy on both ALI and PF in rat models. A total of 48 albino Wistar male rats were included in the study. Lipopolysaccharide (LPS) was used to induce the ALI model, and bleomycin was used for the PF model. The effects of inhaled ozone (O₃) were investigated using the ELISA method. Hematoxylin&eosin staining, Masson’s trichrome staining, and immunohistochemical methods were used for histopathological evaluation. The Interleukin-1 beta (IL-1β), Interleukin-6 (IL-6), Tumor Necrosis Factor-alpha (TNF-α), and Nuclear Factor kappa B subunit p65 (NF-κB p65) levels in the ALI + 0.08 ppm O₃, ALI + 0.12 ppm O₃, PF + 0.08 ppm O₃, and PF + 0.12 ppm O₃ groups statistically decreased to the same extent and approached the levels of control animals. It was observed that IL-1β, IL-6, TNF-α, and NF-κB p65 levels in lung tissues were significantly and dose-dependently decreased compared to the untreated PF and ALI groups, respectively. While fibrosis was severe in the PF + 0.08 ppm O₃ group, it decreased to more moderate levels in the PF + 0.12 ppm O₃ group. The cytokine levels confirmed that inhaled ozone protected the lungs from both ALI and the development of PF.

Butyrylcholinesterase (BChE; EC 3.1.1.8) is an enzyme found in blood plasma and various tissues, playing a key role in metabolizing esters and detoxifying various substances. In this study, we developed a modified purification protocol for BChE from human serum, achieving a higher purification yield (38.3%) and specific activity (15.09 U/mg protein) compared to previous reports. The method employed a single round of acid dialysis, Sephadex G50 gel filtration chromatography, and procainamide Sepharose 4 fast flow affinity chromatography. Our new approach excludes the commonly used DEAE Trisacryl M chromatography. The goal was to compare this method with our previously employed purification protocols. This study demonstrates that optimizing chromatography steps can enhance enzyme recovery and activity, though further refinement may be needed for higher purification folds. This improved methodology offers a valuable approach for efficient BChE purification with potential for broader applications.

Cocoonase is a naturally secreted protease responsible for facilitating moth emergence from inside of cocoon. This protease is considered as of prime importance for all the cocooning lepidopteron. It specifically degrades sericin, the glue protein of the cocoon without damaging the fibroin and makes an escape hatch for adult emergence. Owing to this property cocoonase was characterized and explored for its prospective utilization in eco-friendly enzyme-based silk degumming. However, the applicability of cocoonase has not been explored much other than in silk degumming. Moreover, being a serine protease, and because of its similarity to trypsin, there is, tremendous potential for this enzyme to have biomedical applications, as well as numerous other uses that need to be investigated. This review article presents the comprehensive physicochemical properties of the cocoonase and its possible scope of applications in the near future.

The Ferguson plot is a simple method for determining the molecular weight of native proteins and their complexes. In this study, we tested the validity of the Ferguson plot based on agarose native gel electrophoresis using multimeric chaperone protein, ClpB, derived from a moderate halophile that forms a native hexamer. The Ferguson plot showed a single band with a molecular weight of 1,500 kDa, approximately twice the size of the native hexamer. This result is consistent with the structure of other chaperons that form a double ring assembly comprising two hexameric units, i.e., a dodecamer. Supporting this, dynamic light scattering experiment showed two peaks, which likely correspond to the hexamer and dodecamer structures.

Trypsin inhibitor from the root-tuber of underutilized legume Winged bean (Psophocarpus tetragonolobus (L.) DC.) (WbT-TI) was purified using ion exchange chromatography followed by size-exclusion chromatography. The purified WbT-TI showed a molecular mass of 20,609 Da and an isoelectric point of 5.10. Ultraviolet circular dichroism (UV-CD) and intrinsic fluorescence reported, that WbT-TI interacts with trypsin. Domain-wise analysis of WbT-TI revealed it to belong to the Kunitz-type soybean trypsin inhibitor (STI) family with a specific β-trefoil fold. The sequence of WbT-TI showed 44% sequence coverage to acidic trypsin inhibitor from the seed of the same plant. Protein interaction similarity analysis (PIPSA) evaluated the electrostatic properties of WbT-TI and provided information about the interacting partners of trypsin inhibitors. The purified protein was quantified and tested for in vitro anticancer activity using 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide (MTT) assay against the human osteosarcoma (MG-63) cell line. At 5 µg/ml of WbT-TI, the highest inhibition was seen. These studies may lead to the development of winged bean protease inhibitor-based preventive and therapeutic strategies for different kinds of cancers.

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