A pH-applicative fluorescent probe with long measuring range for monitoring hydrazine in water samples and Arabidopsis thaliana.

In this work, a fluorescent probe, RhodCl-Hz, with pH-applicative capability and long measuring range, was developed to serve the topic on the enrichment process of hydrazine. It was practical due to the clear acid-base boundary and the sectioned linear ranges. With the excitation wavelength of 515 nm and the emission peak at 565 nm, the detecting system was steady. It exhibited a clear cut-off point at pH 7.0 and steady fluorescence signals within the range of 7.0-10.0. As a whole, the linear range of 10.0-500 µM (1.0-50.0 equivalent) was long. The Limit of Detection value was calculated as 0.64 µM. With high selectivity, RhodCl-Hz was applied to suit water samples and biological imaging in both Arabidopsis Thaliana root tips and living MCF-7 cells. The information here might be helpful for revealing the enrichment process of hydrazine.

Synthesis, Crystal Structures, Molecular Docking and MAO-B Inhibitory Activity of Transition Metal Complexes Derived from 2-(4-(Pyridin-2-yl)piperazin-1-yl)acetic Acid.

Three new complexes derived from 2-(4-(pyridin-2-yl)piperazin-1-yl)acetic acid (HL), [M(L)2(H2O)2] where M = CuII (1), ZnII (2) and CdII (3), have been synthesized and characterized by IR spectroscopy, elemental analysis and X-ray crystallography. The inhibitory activity of these three complexes against MAO-B was tested in vitro, and the molecular docking experiments were also carried out to rationalize their binding models. Both the experimental and docking simulation results indicated that complex 1 has the best inhibitory activity with IC50 value being 6.5 ± 0.31 µM.

Study on properties of residue-residue contacts in protein.

Residue-residue contacts are very important in forming protein structure. In this work, we calculated the average probability of residue-residue contacts in 470 globular proteins and analyzed the distribution of contacts in the different interval of residues using Contacts of Structural Units (CSU) and Structural Classification (SCOP) software. It was found that the relationship between the average probability PL and the residue distance L for four structural classes of proteins could be expressed as lgPL=a+b x L, where a and b are coefficients. We also discussed the connection between two aspects of proteins which have equal array residue number and found that the distribution probability was stable (or un-stable) if the proteins had the same (or different) compact (for example synthase) in the same structural class.