A classic example of solid-state topochemical reactions is the ultraviolet-light induced photodimerization of α-trans-cinnamic acid (CA). Here, we report the first observation of an X-ray-induced dimerization of CA and monitor it in situ using nonresonant inelastic X-ray scattering spectroscopy (NRIXS). The time-evolution of the carbon core-electron excitation spectra shows the effects of two X...

Human immunodeficiency virus (HIV)-1 integrase (IN), which mediates integration of viral cDNA into the cellular chromosome, is a validated antiviral drug target. Three IN inhibitors, raltegravir, elvitegravir and dolutegravir, have been clinically approved since 2008. However, drug resistance have emerged in infected patients receiving treatment using these drugs which share the same mechanism ...

The mariner Mos1 synaptic complex consists of a tetramer of transposase molecules that bring together the two ends of the element. Such an assembly requires at least two kinds of protein-protein interfaces. The first is involved in "cis" dimerization, and consists of transposase molecules bound side-by-side on a single DNA molecule. The second, which is involved in "trans" dimerization, consist...

The 5' untranslated leader region of retroviral RNAs contains noncoding information that is essential for viral replication, including signals for transcriptional transactivation, splicing, primer binding for reverse transcription, dimerization of the genomic RNA, and encapsidation of the viral RNA into virions. These RNA motifs have considerable structural and functional overlap. In this study...

The nitric oxide synthases are dimeric enzymes in which the intersubunit contacts are formed by the P-450-haem-containing, tetrahydrobiopterin-dependent oxygenase domain. The dimerization of the neuronal isoenzyme was shown previously to be triggered by Fe-protoporphyrin IX (haemin). We report for the first time the reactivation of the haem-deficient neuronal isoenzyme (from rat, expressed in a...

The unfolded protein response (UPR) is an evolutionarily conserved mechanism by which all eukaryotic cells adapt to the accumulation of unfolded proteins in the endoplasmic reticulum (ER). Inositol-requiring kinase 1 (IRE1) and PKR-related ER kinase (PERK) are two type I transmembrane ER-localized protein kinase receptors that signal the UPR through a process that involves homodimerization and ...

A lattice-based model of a protein and the Monte Carlo simulation method are used to calculate the entropy loss of dimerization of the GCN4 leucine zipper. In the representation used, a protein is a sequence of interaction centers arranged on a cubic lattice, with effective interaction potentials that are both of physical and statistical nature. The Monte Carlo simulation method is then used to...

Targeting protein-protein interactions (PPI) is an emerging field in drug discovery. Dimerization and PPI are essential properties of human immunodeficiency virus (HIV)-1 proteins, their mediated functions, and virus biology. Additionally, dimerization is required for the functional interaction of HIV-1 proteins with many host cellular components. In this study, a bimolecular fluorescence compl...

The role of the sugar moiety of glycopeptide antibiotics in chiral recognition was investigated with capillary electrophoresis. Two glycopeptide antibiotics, vancomycin and balhimycin, were employed as models since they possess the same aglycon and almost identical sugar moieties, however, with different attachment sites to the aglycon. The observed enantioselectivity of balhimycin for dansylat...

Physical dimerization of polycyclic aromatic hydrocarbons (PAHs) has been investigated via molecular dynamics (MD) simulation with the ReaxFF reactive force field that is developed to bridge the gap between the quantum mechanism and classical MD. Dynamics and kinetics of homo-molecular PAH collision under different temperatures, impact parameters, and orientations are studied at an atomic level...