Quantum-Chemical Description of Some Physical-Chemical Properties of Proteinogenic Amino Acids

We describe an impact of the inductive and steric effects of R-groups of amino acids on the reaction center (carboxy and amine groups) to estimate the propensity of amino acids for the peptide bond formation. These effects were quantitatively evaluated using the orders of the C-O and N-H bonds (PCO and PNH), the charges on the carbon, nitrogen and oxygen atoms of the carboxy, amine and hydroxy groups (q(C3), q(N6), q(O2)) and the dipole moments of all amino acids (μ). The calculations were carried out by means of modern quantum-chemical method Density Functional Theory (DFT). many-electron system can be determined by using functionals, which in this case is the spatially dependent electron density. Hence the name of density functional theory comes from the use of functionals of electron density. DFT is among the most popular and versatile methods available in computational biology. Unlike the wavefunction, which is not a physical reality, electron density is a physical characteristic of molecules. Hybrid methods, as the name suggests, attempt to incorporate some of the more useful features from ab initio methods (specifically Hartree-Fock methods) with some of the improvements of DFT mathematics. Hybrid methods, such as B3LYP [9-11] most commonly used for computational chemistry and Biology. Calculations were performed using software,”Priroda-8” in regime of the reaction coordinate [12]. N