Hexahelicene DNA-binding: Minor groove selectivity, semi-intercalation and chiral recognition.

In this contribution, we focused on a fundamental study targeting the interaction of water-soluble [6]helicene derivative 1 (1-butyl-3-(2-methyl[6]helicenyl)-imidazolium bromide) with double-stranded (ds) DNA. A synthetic 30-base pair duplex, plasmid, chromosomal calf thymus and salmon DNA were investigated using electrochemistry, electrophoresis and spectroscopic tools supported by molecular dynamics (MD) and quantum mechanical approaches. Both experimental and theoretical work revealed the minor groove binding of 1 to the dsDNA.

Unique peptidic agonists of a juvenile hormone receptor with species-specific effects on insect development and reproduction.

Juvenile hormones (JHs) control insect metamorphosis and reproduction. JHs act through a receptor complex consisting of methoprene-tolerant (Met) and taiman (Tai) proteins to induce transcription of specific genes. Among chemically diverse synthetic JH mimics (juvenoids), some of which serve as insecticides, unique peptidic juvenoids stand out as being highly potent yet exquisitely selective to a specific family of true bugs.

Explaining the interaction of mangiferin with MMP-9 and NF-ƙβ: a computational study.

Mangiferin is a glycosylated xanthone widely distributed in nature, which exhibits wide pharmacological activities, highlighting its anti-cancer properties. Mangiferin interferes with inflammation, lipid, and calcium signaling, which selectively inhibits multiple NFkB target genes as interleukin-6, tumor necrosis factor, plasminogen, and matrix metalloproteinase, among others. In this work, the interactions of this polyphenol with MMP-9 and NF-κβ are characterized by using computational chemistry methods.

Mechanistic insight into the RNA-stimulated ATPase activity of tick-borne encephalitis virus helicase.

The helicase domain of nonstructural protein 3 (NS3H) unwinds the double-stranded RNA replication intermediate in an ATP-dependent manner during the flavivirus life cycle. While the ATP hydrolysis mechanism of Dengue and Zika viruses NS3H has been extensively studied, little is known in the case of the tick-borne encephalitis virus NS3H. We demonstrate that ssRNA binds with nanomolar affinity to NS3H and strongly stimulates the ATP hydrolysis cycle, whereas ssDNA binds only weakly and inhibits ATPase activity in a noncompetitive manner.

Specific anion effect on properties of HRV 3C protease.

Specific salts effect is intensively studied from the prospective of modification of different physico-chemical properties of biomacromolecules. Limited knowledge of the specific salts effect on enzymes led us to address the influence of five sodium anions: sulfate, phosphate, chloride, bromide, and perchlorate, on catalytic and conformational properties of human rhinovirus-14 (HRV) 3C protease. The enzyme conformation was monitored by circular dichroism spectrum (CD) and by tyrosines fluorescence.