Nanodiamonds synthesized by detonation have been found not to immobilize the ring form of pUC19 plasmid DNA. Linear pUC19 molecules with blunt ends, prepared by restriction of the initial ring form of pUC19 DNA, and linear 0.25-10 kb DNA fragments are adsorbed on nanodiamonds. The amount of adsorbed linear DNA molecules depends on the size of the molecules and the size of the nanodiamond clusters.

A method for single nucleotide polymorphism identification was developed, which was based on the primer extension reaction (PEXT) followed by bioluminescent solid-phase microassay. Recombinant Ca²⁺-regulated photoprotein obelin and coelenterazine-dependent Renilla muelleri luciferase were used as reporters. The study was performed as an example of SNP genotyping of the human F5 gene encoding human Factor V Leiden polymorphism 1691 G→A (R506Q). Genomic DNA was amplified by PCR using primers flanking polymorphic site of 140 base pairs. PCR products were used as templates for two PEXT reactions using two primers containing 3′-terminal nucleotides, which were complementary to either normal or mutant alleles. If the template and allele-specific primer were completely complementary, the latter was elongated with DNA polymerase. The resulting extension product contained biotin residue due to the presence of biotinylated deoxyuridine triphosphate (B-dUTP) in the reaction mixture. The products were analyzed using obelin-streptavidin conjugates. The optimal PEXT-reaction conditions were found, which ensured a high reliability of SNP genotyping. A new approach to simultaneously revealing both alleles in one well was developed using two bioluminescent reporters. The efficiency of the proposed approach was shown in the study of clinical DNA samples.

Detecting the folding/unfolding pathways of biological macromolecules is one of the urgent problems of molecular biophysics. The unfolding of bacterial luciferase from Vibrio harveyi is well-studied, unlike that of Photobacterium leiognathi, despite the fact that both of them are actively used as a reporter system. The aim of this study was to compare the conformational transitions of these luciferases from two different protein subfamilies during equilibrium unfolding with urea. Intrinsic steady-state and time-resolved fluorescence spectra and circular dichroism spectra were used to determine the stages of the protein unfolding. Molecular dynamics methods were applied to find the differences in the surroundings of tryptophans in both luciferases. We found that the unfolding pathway is the same for the studied luciferases. However, the results obtained indicate more stable tertiary and secondary structures of P. leiognathi luciferase as compared to enzyme from V. harveyi during the last stage of denaturation, including the unfolding of individual subunits. The distinctions in fluorescence of the two proteins are associated with differences in the structure of the C-terminal domain of α-subunits, which causes different quenching of tryptophan emissions. The time-resolved fluorescence technique proved to be a more effective method for studying protein unfolding than steady-state methods.