Mass Spectrometric and Bio-Computational Binding Strength Analysis of Multiply Charged RNAse S Gas-Phase Complexes Obtained by Electrospray Ionization from Varying In-Solution Equilibrium Conditions

We investigated the influence of a solvent’s composition on the stability of desorbed and multiply charged RNAse S ions by analyzing the non-covalent complex’s gas-phase dissociation processes. RNAse S was dissolved in electrospray ionization-compatible buffers with either increasing organic co-solvent content or different pHs. The direct transition of all the ions and the evaporation of the solvent from all the in-solution components of RNAse S under the respective in-solution conditions by electrospray ionization was followed by a collision-induced dissociation of the surviving non-covalent RNAse S complex ions. Both types of changes of solvent conditions yielded in mass spectrometrically observable differences of the in-solution complexation equilibria. Through quantitative analysis of the dissociation products, i.e., from normalized ion abundances of RNAse S, S-protein, and S-peptide, the apparent kinetic and apparent thermodynamic gas-phase complex properties were deduced. From the experimental data, it is concluded that the stability of RNAse S in the gas phase is independent of its in-solution equilibrium but is sensitive to the complexes’ gas-phase charge states. Bio-computational in-silico studies showed that after desolvation and ionization by electrospray, the remaining binding forces kept the S-peptide and S-protein together in the gas phase predominantly by polar interactions, which indirectly stabilized the in-bulk solution predominating non-polar intermolecular interactions. As polar interactions are sensitive to in-solution protonation, bio-computational results provide an explanation of quantitative experimental data with single amino acid residue resolution.

PENGARUH PENGGUNAAN BLENDED LEARNING BERBASIS SCHOOLOGY TERHADAP HASIL BELAJAR PESERTA DIDIK PADA MATERI HIDROLISIS GARAM

This research aimed at increasing student learning achievement on Ion and pH Saline Solution Equilibrium lesson by using Schoology blanded Learninglearning model. Qualitative method was used in this research with quasi- experimental research design. All the eleventh-grade students of Natural Science of State Senior High School 1 TapungHilir in the Academic Year of 2018/2019 were the population of this research, and the samples were the eleventh-grade students of Natural Science 1 as the experimental group and the students of Natural Science 2 as the control group. Pretest-posttest control group design was used in this research. Sampling was done by using random technique. Analyzing the data was using one-way ANOVA. The data were analyzed by using inferential statistic with the help of SPSS 16.0 software. The results of calculating the data showed that the score of Sig. was lower than α, the significance score was 0.003. It showed that the learning achievement mean on Ion and pH Saline Solution Equilibrium lesson was increasing through the use of Schoology based Blended Learning. It could be concluded that there was an effect of using Schoology- based Blended Learning toward student learning achievement on Ion and pH Saline Solution Equilibrium lesson.

Factors determining the metal ion binding ability and selectivity of hydroxamate based compounds

: There has been a long tradition for a broad spectrum of applications of both natural and synthetic hydroxamic acids and derivatives. Even nowadays, a huge number of newly designed representatives (from different monohydroxamate-based compounds to siderophore conjugates) are intended to develop potential drug candidates with desired activities. Since these compounds are effective metal-chelating agents their biological roles and actions as well as their various applications e.g. in the medicinal practice are all in direct correlation with their metal complexation. Consequently, the knowledge of the stoichiometry and binding modes of metal complexes with hydroxamic acid based ligands, their thermodynamic parameters, speciation profiles in solution is crucial for scientists working at any of the above-mentioned fields. This review, in addition to presenting a few factors, which might affect the metal binding capabilities of these organic ligands, displays and summarizes the different parameters typically used to give the stoichiometry/composition and stability of the species formed in a solution equilibrium system in measurable concentration. Discussion of the possibilities for quantitative comparison of metal binding effectivity and selectivity of various hydroxamic acids with each other by using solution equilibrium data is also in the focus of this publication.

Adsorption of Ni2+ and Cu2+ Ions from Wastewater by a Silanized Zeolite Produced with a 3-Mercaptopropyl Trimethoxysilane Modification

Adsorption characteristics of a silanized zeolite for Ni2+ and Cu2+ ions in water solutions were analyzed by SEM, FTIR and XRD techniques. For ion removal, an optimum ratio of 1 g/L silanized zeolite was obtained for adsorbing a Ni2+ and Cu2+ solution. Equilibrium states at 220 and 108 min were reached for the adsorption of Ni2+ and Cu2+, respectively. In a pH range of 2–6, the modified zeolite demonstrated an excellent resistance to acids by exhibiting a high adsorption capacity, which increased with a larger pH.

A transient non-covalent hydrogel by a supramolecular gelator with dynamic covalent bonds

In aqueous solution, equilibrium self-assembly and gelation occur at higher concentration but on addition of EDC non-equilibrium self-assembly and transient hydrogels are formed at low concentration, which dissolve upon anhydride hydrolysis.