Articles
Biochemical and Biophysical Research Communications (0006291X)758
Alzheimer's disease involves the accumulation of amyloid beta (Aβ) monomers that form oligomers and fibrils in the brain. Studying the Aβ monomer is critical for understanding Aβ assembly and peptide behavior and has implications for drug design. Choosing a starting structure with a higher aggregation tendency for cost-effective MD studies and drug design is crucial. Previous studies have utilized distinct initial conformations, leading to varying results. Hence, this study was conducted to compare different initial conformations using the same MD simulation protocol to investigate the behavior and oligomerization propensity of different starting structures of Aβ during 1μs. The behavior of the monomers and their self-assembly systems were studied thoroughly, and the results revealed that highly helical Aβ monomers which used as starting structures retain high helix content during the simulation, and their tautomerization states did not cause significant changes in the structure. On the other hand, the Aβ extended and S-shaped monomers displayed the fingerprints of the fibril structure, which is believed to be more favorable for self-assembly. Self-assembly behaviors were seen for three S-shaped and three Aβ extended peptides. However, both conformations did not show stable β-sheet intermolecular interaction. For the Aβ16-22 monomer as a fragment of the Aβ that can assemble into fibrils, the impacts of capping and uncapping on the initial structure were also investigated. The results displayed that capped and uncapped structures can form oligomers with β-sheet at termini. However, in the capped state, β-sheet interactions were more stable and remained relatively longer than uncapped. © 2025 Elsevier Inc.
Khani, L.,
Nikfar, N.,
Zakeri, S.,
Rahmati, M.,
Javdan, S.,
Ganjalikhany, M.R.,
Fouladseresht, H.,
Ataei, B.,
Didarian, R.,
Ganjalikhani-hakemi, M. Infection, Epidemiology And Microbiology (25884115)11(2)pp. 167-178
Background: The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), poses a significant global health threat. The host immune response determines the disease severity, with factors like human leukocyte antigen (HLA) genes, age, sex, and nutritional status influencing outcomes. HLA genes, known for their genetic diversity, are implicated in determining susceptibility and severity of infectious diseases. This study investigated the association between HLA class I genotypes and COVID-19 severity in the Isfahan population, Iran. Materials & Methods:Blood samples were collected from 34 COVID-19 patients with varying levels of disease severity (severe, moderate, and mild). HLA genotyping was performed using polymerase chain reaction-sequence specific primers (PCR-SSP), and in silico analysis assessed the affinity of viral peptides to HLA alleles. Findings: Statistical analyses revealed that HLA-C07 was more prevalent in patients with severe COVID-19, suggesting a potential association between this allele and the disease severity. Furthermore, HLA-A01 was more prevalent among severe cases, while HLA-A02 and HLA-A03 were less frequent, indicating a possible predisposing role for HLA-A01 and protective roles for HLA-A02 and HLA-A*03. Conclusion: These findings highlight the role of HLA molecules in COVID-19 severity and offer insights into genetic factors influencing outcomes. Understanding the association of specific HLA alleles, such as HLA-C07, HLA-A01, HLA-A02, and HLA-A03, with the disease progression lays a foundation for advancing personalized preventive and therapeutic approaches. These results contribute to knowledge on host genetics in infectious diseases, paving the way for further research and therapeutic strategies. © 2025, TMU Press.