Inductive effects in amino acids and peptides: Ionization constants and tryptophan fluorescence
Por:
Lara-Popoca, Jesus, Thoke, Henrik S., Stock, Roberto P., Rudino-Pinera, Enrique, Bagatolli, Luis A.
Publicada:
1 dic 2020
Resumen:
Although inductive effects in organic compounds are known to influence
chemical properties such as ionization constants, their specific
contribution to the properties/behavior of amino acids and functional
groups in peptides remains largely unexplored. In this study we
developed a computationally economical algorithm for ab initio
calculation of the magnitude of inductive effects for non-aromatic
molecules. The value obtained by the algorithm is called the Inductive
Index and we observed a high correlation (R-2 = 0.9427) between our
calculations and the pK(a) values of the alpha-amino groups of amino
acids with non-aromatic side-chains. Using a series of modified amino
acids, we also found similarly high correlations (R-2 > 0.9600) between
Inductive Indexes and two wholly independent chemical properties: i) the
pK(a) values of ionizable side-chains and, ii) the fluorescence response
of the indole group of tryptophan. After assessing the applicability of
the method of calculation at the amino acid level, we extended our study
to tryptophan-containing peptides and established that inductive
contributions of neighboring side-chains are transmitted through peptide
bonds. We discuss possible contributions to the study of proteins.
Filiaciones:
Lara-Popoca, Jesus:
Instituto de Biotecnología, Universidad Nacional Autónoma de México, Departamento de Medicina Molecular y Bioprocesos, Av. Universidad #2001, Col. Chamilpa, Cuernavaca, Morelos 62210, Mexico
Thoke, Henrik S.:
MEMPHYS - International and Interdisciplinary Research Network, Odense, Denmark
Stock, Roberto P.:
Instituto de Biotecnología, Universidad Nacional Autónoma de México, Departamento de Medicina Molecular y Bioprocesos, Av. Universidad #2001, Col. Chamilpa, Cuernavaca, Morelos 62210, Mexico
Rudino-Pinera, Enrique:
Instituto de Biotecnología, Universidad Nacional Autónoma de México, Departamento de Medicina Molecular y Bioprocesos, Av. Universidad #2001, Col. Chamilpa, Cuernavaca, Morelos 62210, Mexico
Bagatolli, Luis A.:
MEMPHYS - International and Interdisciplinary Research Network, Odense, Denmark
Instituto de Investigación Médica Mercedes y Martín Ferreyra (INIMEC-CONICET-Universidad Nacional de Córdoba), Friuli 2434, Córdoba, 5016, Argentina
Gold, Green Published
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