Juan Alexander Padrón-García's research while affiliated with University of Information Sciences and other places

Publications (11)

Article
The purpose of this work is the definition and evaluation of both atomic and local new hybrid indices. Inspired by the Refractotopological State Index for Atoms, the new atomic indices are theoretically supported by graph theory principles. The local indices, named Descriptor Centres (DCs), are obtained from the sum of the atomic values of the atom...
Article
The IA(3) polypeptide inhibitor from Saccharomyces cerevisiae interacts potently and selectively with its target, the S. cerevisiae vacuolar aspartic proteinase (ScPr). Upon encountering the enzyme, residues 2-32 of the intrinsically unstructured IA(3) polypeptide become ordered into an almost-perfect alpha-helix. In previous IA(3) mutagenesis stud...
Article
We propose two models of the human S-arrestin/rhodopsin complex in the inactive dark adapted rhodopsin and meta rhodopsin II form, obtained by homology modeling and knowledge based docking. First, a homology model for the human S-arrestin was built and validated by molecular dynamics, showing an average root mean square deviation difference from th...
Article
Very large molecular systems can be calculated with the so called CNDOL approximate Hamiltonians that have been developed by avoiding oversimplifications and only using a priori parameters and formulas from the simpler NDO methods. A new diagonal monoelectronic term named CNDOL/21 shows great consistency and easier SCF convergence when used togethe...
Article
Association between NO and each of the 20 amino acids and their related organic functional groups was studied by exploring the configuration space of the potential energy of association surface by using the multiple minima hypersurface procedure. AM1 semiempirical Hamiltonian was used in order to explore such complex hypersurfaces of biological mol...
Article
Full-text available
The recently defined molar-refractivity-partition index was applied to a family of 1,3,5- thiadiazin-2-thione derivatives in order to establish quantitative structure-antitumoral models. The goal of this effort is to establish the relationships between the structure and biological response of these compounds. After the splitting of the sample in tw...
Article
Full-text available
Abstract Purpose. The recently defined molar-refractivity-partition index was applied to a family of 1,3,5- thiadiazin-2-thione derivatives in order to establish quantitative structure-antitumoral models. The goal of this effort is to establish the relationships between the structure and biological response of these compounds. Method. After the spl...
Article
Changes induced by mutations in rhodopsin that are associated with the degenerative visual disease retinitis pigmentosa result in an altered pattern of light absorption according to quantum mechanical simulations and reference experimental works. Eleven single-point mutations associated with retinitis pigmentosa at and in the proximity to the retin...
Article
The present work explores the effect of substitution in all free positions of furfural on conformational preferences of formyl group by using ab-initio calculations at the MP2/6-31G(p,d) level of theory. Theoretical modeling was made in vacuo. The selected substituents were -CH(3), NH(2), NO(2) and F groups in 3, 4, 5 and ipso carbonyl positions. G...
Article
Full-text available
The topological and topographical indices are broadly used tools in molecular modeling studies. Its computer easiness and high descriptive capacity of the chemical structure confers it a great applicability in the field of chemical-physical and biological properties prediction. On the other hand, the solvent accessible surface area is a theoretic...

Citations

... Technological evolution has given place to the born of powerful computer software of outstanding utilities in the construction of predictive models of convinent interpretation and relative simplicity based on the quantitative dependence between property of interest and molecular structure (QSPR). [3][4][5] In the particular case of antimicrobials for topical use, the following physicochemical mesurements compose strong influence in their pharmacological performance, which are solubility (S), partition coefficient (P), distribution constant (D), acid dissociation constant (K a ) and the superficial tension (σ). A profound knowledge of the relation between these properties and chemical structure of interest is essential not only to successfully develop a new pharmaceutical candidate, but also to enhance the behavior of already existed molecules. ...
... The reduction of the chemical graph is carried out by the method described by Carrasco et al. [35], where the descriptor centers (DCs), rings of different orders (Rn), clusters of order 3 and 4 (C3 and C4, respectively), heteroatoms such as halogens, amino, etc. (X), and terminal groups such as methyl ( M 3 ), methylene ( M 2 ) and ...
... MMH methodology combines a quantum semi-empirical methods for the evaluation of the energies with statistical mechanics to obtain thermodynamic quantities related to the molecular association process [53][54][55][56][57][58][59][60][61]. The main procedure of this approach will be outlined briefly. ...
... Therefore, design and prediction of their activity is one the most challenging areas in bio sciences due to large amount of arrangement possibilities. In this regard, computational study of amino acids and peptides has a considerable portion in the studying and designing of the peptides [3,4]. ...
... This mutation was classified as a missense mutation allegedly replacing the methionine at position 207 with an arginine (Met207Arg) and is listed as such in a set of publications addressing rhodopsin function or therapy (e.g. (11)(12)(13)(14)(15)(16)(17)(18)(19)). All affected patients suffer from a severe, early-onset adRP. ...
... The derivative 3-(2-furfuryl)-5-(α-carbamidomethyl)carboximethyl tetrahydro-2H-1,3,5-thiadiazine-2-thione (21) (Figure 7), bearing furfuryl and L-asparagine moieties, yielded the most interesting compound, which is a candidate for a future anticancer study [24]. These results allowed the application of QSAR methodology to study mono-THTT derivatives using the novel hybrid index pMRχ [46]. Recently, two series were synthesized to develop new cell cycle inhibitors [47]. ...
... CrysFML [27]) preserve this language as the preferred one among the creators of "number crunching" programs. As support for the aforesaid tendency, we mention that FORTRAN is the language in which most of the highly cited programs for quantum chemistry [28][29][30][31][32] and X-ray crystallography [33,34] have been written. The mixed programing between Python and FORTRAN has been done as follows. ...
... Co-segregation analysis showed that the three mutations co-segregated with the disease phenotype in the tested family members, and was absent in 100 controls ( Fig 1). The missense substitution c.1040C>T (p.P347L) was reported as pathogenic and is a hotspot in adRP families [11][12][13]. The missense substitution c.632A>T (p.H211L) is novel, but the pathogenic variants p.H211P and p.H211R were previously reported [14][15]. ...