The Protein Journal最新文献

Butyrylcholinesterase (BChE; EC 3.1.1.8), a serine hydrolase found in various tissues, hydrolyses choline esters such as acetylcholine and succinylcholine, as well as other esters such as heroin and acetylsalicylic acid. It is considered to play a role in lipid metabolism as it belongs to the same enzyme group as lipases and its catalytic subunits are similar. In this study, the effects of unsaturated fatty acids, namely arachidonic (AA), linoleic (LA), alpha-linolenic (ALA) and oleic acid (OA), on equine serum BChE (EqBChE) were investigated. Enzyme activity was measured by the modified Ellman method. When the activity results were evaluated, the IC50 values were found 45.49, 8.465, 1556, and 56.57 μM; while the Ki values were 63.92, 11.46, 1800, and 15.24 μM for AA, ALA, LA, and OA, respectively. Analysis of the kinetic results showed that ALA was compatible with mixed inhibition and other fatty acids were compatible with non-competitive inhibition, a special type of mixed inhibition. Molecular docking predicted binding of the fatty acids to the active site, as well as to predicted allosteric sites. The results of this study provide another support to the hypothesis that cholinesterases are associated with lipid metabolism.

Factors that impede the normal growth and development of plants are termed ‘stress factors’ and result in yield loss. Exposure to elevated concentrations of heavy metals has been demonstrated to induce the production of reactive oxygen species (ROS), which can affect physiological and biochemical processes. The present study investigated the effects of two common heavy metals (Hg²⁺ and Cd²⁺) on specific physiological and biochemical parameters of sorghum (Sorghum bicolor (L.) Moench). The study utilized doses ranging from 3 to 15 ppm for the application of heavy metals. The study focused on the effects of these metals on the activities of enzymes (superoxide dismutase and peroxidase), chlorophyll content, fresh weight, dry weight, and proline content in sorghum plants. The study found that applying mercury at 9 ppm resulted in the highest activity of peroxidase (POX), with an observed increase of 69.57% compared to the control. Conversely, cadmium application at 12 ppm elicited the highest activity, increasing by 102.17% compared to the control. For superoxide dismutase (SOD), the peak activity was observed at 6 ppm for both applications, with an increase of 84.16% in the mercury application control group and 121.08% in the cadmium application group compared to the control group. A similar pattern was observed in the chlorophyll content, which initially increased and then decreased. Declines in fresh weight, dry weight, and proline accumulation were also documented.

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disorder and its concurrent presence with chronic kidney disease (CKD) is a significant concern. Glycerol kinase (GK) and glycerol 3-phosphate shuttle enzymes (cGPDH and mGPDH) facilitate the regulation of endogenous glucose production in many cell lines. This research investigates the functions of GK, cGPDH, and mGPDH in HEK293 cells. Standard protocols were employed to assess enzyme activity, mRNA- and protein-expression, glucose uptake, and production. Homology modeling and molecular docking were employed to elucidate interactions of genistein and metformin with these enzymes. The secondary structures of GK, cGPDH and mGPDH and the thermal stability of cGPDH and mGPDH were analyzed by CD spectra. Genistein inhibited GK activity by 40%, while metformin decreased cGPDH and mGPDH activity by 58% and 55%, respectively, in HEK293 cells. Nonetheless, the expression levels of mRNA and protein remained unaltered. Genistein and metformin inhibited HEK293 glucose production by 0.46-fold and 0.63-fold, respectively. Genistein reduced glucose uptake by 0.26-fold, while metformin increased it by 0.51-fold. Genistein allosterically interacted with GK with a CDocker energy of -27.71, while metformin interacted with Gln295 and Lys296 of the catalytic loop of cGPDH and the FAD⁺ binding domain of mGPDH, yielding CDocker energies of -11.12 and -13.34, respectively. This study indicated the role of genistein and metformin on GK, cGPDH, and mGPDH in HEK293 cells.

Malaria remains a formidable challenge to global health, claiming the lives of nearly half a million individuals annually despite vigorous efforts to curb its spread. Among the myriad factors influencing the persistence and virulence of this disease, the role of specific proteins during the Plasmodium development cycle is critical. The protein of interest, Pfs16, is a Parasitophorous Vacuole Membrane Protein expressed from the earliest asexual stages, which encompass the development of Plasmodium falciparum in the host, to the final stage of the parasite's development in the mosquito, the sporozoite, playing a crucial role in this lifecycle. Understanding the function and mechanism of this conserved protein is pivotal for advancing our strategies to combat malaria. In this review, we examine the work on Pfs16 in both the asexual and sexual stages of parasite development, aiming to gain a better understanding of this protein as a promising candidate for drug and vaccine development.

Plant-derived cysteine proteases have emerged as a compelling subject of investigation, capturing scientific interest owing to their potential applications in diverse industries, including food and biotechnology. This study focused on isolating Kaempferia galanga cysteine protease (KgCP) from rhizomes of Kaempferia galanga, followed by a comprehensive characterization of the protease. It was purified and characterized using various biochemical and biophysical techniques, including anion-exchange chromatography, gel filtration, SDS-PAGE electrophoresis, and enzyme assays. With a yield of 23.2%, the purification process generated a 6.03-fold increase in specific activity. KgCP’s molecular weight was determined to be around 33 kDa and exhibited optimal catalytic performance at 55 °C and pH 5.5. Values of its catalytic parameters, V_max and K_m, were found to be 103.7 Units min⁻¹ and 0.025 μmol, respectively. Inhibition of KgCP by various cysteine protease inhibitors – E-64, iodoacetamide, and mercury chloride confirmed it to be a cysteine protease. The inclusion of detergents and organic solvents did not affect the stability of KgCP. Although proteolytic activity was compromised by metal ions such as Cd²⁺, Co²⁺, and Fe³⁺, other metal ions (Ca²⁺, Mg²⁺, Mn²⁺, Sn²⁺, Sr²⁺, etc.) showed negligible impact on its proteolytic activity. These findings expand our understanding of the biological characteristics of this cysteine protease, highlighting its potential for applications in the dairy industry, bioactive peptide synthesis, detergents industry, etc. The entire work can be graphically presented as follows:

Graphical abstract

Antibiotic resistance, driven by the rise of pathogens like VRE and MRSA, poses a global health threat, prompting the exploration of antimicrobial peptides (AMPs) as alternatives to traditional antibiotics. AMPs, known for their broad-spectrum activity and structural flexibility, share characteristics with intrinsically disordered proteins, which lack a rigid structure and play diverse roles in cellular processes. This study aims to quantify the intrinsic disorder and liquid–liquid phase separation (LLPS) propensity in AMPs, advancing our understanding of their antimicrobial mechanisms and potential therapeutic applications. To investigate the propensity for intrinsic disorder and LLPS in AMPs, we compared the AMPs to the human proteome. The AMP sequences were retrieved from the AMP database (APD3), while the human proteome was obtained from the UniProt database. We analyzed amino acid composition using the Composition Profiler tool and assessed intrinsic disorder using various predictors, including PONDR® and IUPred, through the Rapid Intrinsic Disorder Analysis Online (RIDAO) platform. For LLPS propensity, we employed FuzDrop, and FuzPred was used to predict context-dependent binding behaviors. Statistical analyses, such as ANOVA and χ² tests, were performed to determine the significance of observed differences between the two groups. We analyzed over 3000 AMPs and 20,000 human proteins to investigate differences in amino acid composition, intrinsic disorder, and LLPS potential. Composition analysis revealed distinct differences in amino acid abundance, with AMPs showing an enrichment in both order-promoting and disorder-promoting amino acids compared to the human proteome. Intrinsic disorder analysis, performed using a range of predictors, consistently demonstrated that AMPs exhibit higher levels of predicted disorder than human proteins, with significant differences confirmed by statistical tests. LLPS analysis, conducted using FuzDrop, showed that AMPs had a lower overall propensity for LLPS compared to human proteins, although specific subsets of AMPs exhibited high LLPS potential. Additionally, redox-dependent disorder predictions highlighted significant differences in how AMP and human proteins respond to oxidative conditions, further suggesting functional divergences between the two proteomes. CH-CDF plot analysis revealed that AMPs and human proteins occupy distinct structural categories, with AMPs showing a greater proportion of highly disordered proteins compared to the human proteome. These findings underscore key molecular differences between AMPs and human proteins, with implications for their antimicrobial activity and potential therapeutic applications. Our study reveals that AMPs possess a significantly higher degree of intrinsic disorder and specific subsets exhibit LLPS potential, distinguishing them from the human proteome. These molecular characteristics likely contribute to their antimicrobial function an