Ikechukwu Achilonu

Aberrant protein glycosylation is a key driver of colorectal cancer (CRC) progression, contributing to tumour growth, metastasis, and immune evasion. In this study, computational approaches were employed to explore the potential of Brefeldin A as an inhibitor of two glycosylation-associated regulatory proteins: Protein Kinase C alpha (PrKCα) and Mitogen-Activated Protein Kinase 1 (MAPK1). Using computational docking and structural analyses, Brefeldin A was predicted to bind effectively to both targets, thereby inhibiting their enzymatic activities. Detailed investigations revealed that Brefeldin A interacts favourably within the active sites of MAPK1 and PrKCα, forming stable complexes by optimal binding interactions. Key residues contributing to binding stabilisation were identified in both MAPK1 and PrKCα. For MAPK1, residues such as Lys114 and Ser153 played a significant role in hydrogen bonding interactions, while for PrKCα, Gln105, Asn154, and Asp167 were notably involved. These interactions included both hydrogen bonds and hydrophobic contacts, which collectively contributed to the strength and specificity of ligand binding. The identification of these residues provides insight into the molecular mechanisms underlying the stabilisation of the Brefeldin A-kinase complexes. Binding affinity estimations showed that Brefeldin A bound to MAPK1 exhibited a binding energy of −22.18 ± 4.50 kcal/mol. In contrast, the Brefeldin A bound to PrKCα demonstrated a slightly stronger binding energy of −23.90 ± 5.36 kcal/mol. Collectively, these findings underscore Brefeldin A’s potential as a novel inhibitor targeting glycosylation-related proteins in CRC, offering a promising therapeutic strategy to impede CRC progression. This work not only proposes Brefeldin A as a promising therapeutic lead but also supports glycosylation inhibition as a valuable approach for CRC control, with broader implications for drug discovery in glycan-related oncogenic pathways.

Trypanosoma brucei, the causative agent of Human African Trypanosomiasis (HAT), relies exclusively on purine salvage for nucleotide biosynthesis, making its nucleotide-processing enzymes attractive drug targets. Here, we present a comprehensive structural and functional characterization of T. brucei’s nucleoside diphosphate kinase B (TbNDPK), a key enzyme in nucleotide homeostasis. Circular dichroism and fluorescence spectroscopy revealed that TbNDPK is highly stable under thermal and chemical stress and undergoes nucleotide-induced conformational changes. This study also presents high-resolution crystal structures of the apo enzyme and complexes with UDP, CDP, and GDP, showing a conserved hexameric fold, with induced-fit binding via a flexible loop involving Phe59 and key active-site residues. Enzymatic assays revealed substrate preferences for UDP and GDP, while deoxyribonucleotide diphosphates were processed with significantly reduced efficiency. Molecular dynamics simulations revealed ligand-dependent flexibility and subunit-specific nucleotide dynamics, indicating potential asymmetry and cooperative communication within the hexamer. Collectively, these findings position TbNDPK as a thermostable, catalytically efficient, and structurally distinct enzyme optimized for ribonucleotide metabolism and support its potential as a selective target for future antitrypanosomal drug discovery.

Introduction: In the face of increasing antimicrobial resistance, ESKAPE pathogens— Enterococcus faecium , Staphylococcus aureus , Klebsiella pneumoniae , Acinetobacter baumannii , Pseudomonas aeruginosa, and Enterobacter species —pose a significant threat to public health, particularly in nosocomial settings. Areas covered: This review explores the potential of targeting protein adenylyltransferase (PrAT) as a therapeutic strategy against these multidrug-resistant bacteria. We discuss the mechanisms of PrAT activity, its involvement in reduction–oxidation (redox) homeostasis, and the rationale for its potential as a drug target against ESKAPE pathogens. Expert opinion: PrAT plays an essential role in sustaining the bacterium’s redox homeostasis, a vital aspect of bacterial survival, by interacting with glutaredoxin (Grx). Future research should focus on elucidating the specific role of PrAT in ESKAPE pathogens, with an emphasis on studying the enzyme’s function and designing targeted inhibitors. This review underscores the importance of continued investigation into PrAT in ESKAPE pathogens as a critical step in addressing the challenges of antimicrobial resistance in clinical practice.

Aberrant protein glycosylation is a key driver of colorectal cancer (CRC) progression, contributing to tumour growth, metastasis, and immune evasion. In this study, computational approaches were employed to explore the potential of Brefeldin A (BFA) as an inhibitor of two glycosylation-associated regulatory proteins: Protein Kinase C (PrKC1) and Mitogen-Activated Protein Kinase (MAPK). Molecular docking and structural analysis revealed that BFA binds stably and specifically to the active sites of both proteins, suggesting its ability to modulate their function. Detailed interaction profiling identified key active site residues involved in hydrogen bonding, hydrophobic interactions, and van der Waals forces—further supporting the structural compatibility and specificity of BFA for these targets. The optimal binding poses observed indicate potential allosteric or competitive inhibition mechanisms, which could disrupt critical signaling pathways linked to glycosylation and tumour progression. In addition, Binding free energy estimations indicated strong interactions, with BFA-MAPK and BFA-PrKC1 complexes yielding favorable binding affinities of -22.18 ± 4.50 kcal/mol and -23.90 ± 5.36 kcal/mol, respectively. These values highlight the thermodynamic stability of the complexes and suggest a high likelihood of inhibitory activity under physiological conditions. Collectively, these findings underscore BFA’s potential as a novel inhibitor targeting glycosylation-related kinases in CRC. This work not only proposes BFA as a promising therapeutic lead but also supports glycosylation inhibition as a strategic avenue for CRC control, with broader implications for drug discovery in glycan-related oncogenic pathways.

Protein glycosylation plays a crucial role in cancer biology, influencing essential cellular processes such as cell signalling, immune recognition, and tumour metastasis. Therefore, this study highlights the therapeutic potential of targeting glycosylation in cancer treatment, as modulating these modifications could disrupt the fundamental mechanisms driving cancer progression and improve therapeutic outcomes. Recently, Tunicamycin C, a well-known glycosylation inhibitor, has shown promise in breast cancer treatment but remains unexplored in colorectal cancer (CRC). Thus, in this study, we aimed to understand the potential action of Tunicamycin C in CRC using in silico studies to identify possible drug targets for Tunicamycin C. First, we identified two target proteins using the HTDocking algorithm followed by GO and KEGG pathway searches: thymidine kinase 1 (TK1) and cAMP-dependent protein kinase catalytic subunit alpha (PKAc). Following this, molecular dynamics modelling revealed that Tunicamycin C binding induced a conformational perturbation in the 3D structures of TK1 and PKAc, inhibiting their activities. This interaction led to a stable design, promoting optimal binding of Tunicamycin C in the hydrophobic pockets of TK1 and PKAc. Serial validation studies highlighted the role of active site residues in binding stabilisation. Tunicamycin C exhibited high binding affinity with TK1 and PKAc. This study provides a way to explore and repurpose novel inhibitors of TK1 and PKAc and identify new therapeutic targets, which may block glycosylation in cancer treatment.