TY - JOUR

T1 - Photoinduced Processes in Lysine-Tryptophan-Lysine Tripeptide with L and D Tryptophan

AU - Ageeva, Aleksandra A

AU - Lukyanov, Roman S

AU - Martyanova, Sofia O

AU - Magin, Ilya M

AU - Kruppa, Alexander I

AU - Polyakov, Nikolay E

AU - Plyusnin, Victor F

AU - Doktorov, Alexander B

AU - Leshina, Tatyana V

N1 - Funding: This research was funded by Russian Science Foundation, grant number 18-13-00047.

PY - 2023/2/7

Y1 - 2023/2/7

N2 - Optical isomers of short peptide Lysine-Tryptophan-Lysine (Lys-{L/D-Trp}-Lys) and Lys-Trp-Lys with an acetate counter-ion were used to study photoinduced intramolecular and intermolecular processes of interest in photobiology. A comparison of L- and D-amino acid reactivity is also the focus of scientists' attention in various specialties because today, the presence of amyloid proteins with D-amino acids in the human brain is considered one of the leading causes of Alzheimer's disease. Since aggregated amyloids, mainly Aβ42, are highly disordered peptides that cannot be studied with traditional NMR and X-ray techniques, it is trending to explore the reasons for differences between L- and D-amino acids using short peptides, as in our article. Using NMR, chemically induced dynamic nuclear polarization (CIDNP) and fluorescence techniques allowed us to detect the influence of tryptophan (Trp) optical configuration on the peptides fluorescence quantum yields, bimolecular quenching rates of Trp excited state, and the photocleavage products formation. Thus, compared with the D-analog, the L-isomer shows a greater Trp excited state quenching efficiency with the electron transfer (ET) mechanism. There are experimental confirmations of the hypothesis about photoinduced ET between Trp and the CONH peptide bond, as well as between Trp and another amide group.

AB - Optical isomers of short peptide Lysine-Tryptophan-Lysine (Lys-{L/D-Trp}-Lys) and Lys-Trp-Lys with an acetate counter-ion were used to study photoinduced intramolecular and intermolecular processes of interest in photobiology. A comparison of L- and D-amino acid reactivity is also the focus of scientists' attention in various specialties because today, the presence of amyloid proteins with D-amino acids in the human brain is considered one of the leading causes of Alzheimer's disease. Since aggregated amyloids, mainly Aβ42, are highly disordered peptides that cannot be studied with traditional NMR and X-ray techniques, it is trending to explore the reasons for differences between L- and D-amino acids using short peptides, as in our article. Using NMR, chemically induced dynamic nuclear polarization (CIDNP) and fluorescence techniques allowed us to detect the influence of tryptophan (Trp) optical configuration on the peptides fluorescence quantum yields, bimolecular quenching rates of Trp excited state, and the photocleavage products formation. Thus, compared with the D-analog, the L-isomer shows a greater Trp excited state quenching efficiency with the electron transfer (ET) mechanism. There are experimental confirmations of the hypothesis about photoinduced ET between Trp and the CONH peptide bond, as well as between Trp and another amide group.

KW - NMR

KW - UV-irradiation

KW - biradical-zwitterions

KW - chemical polarization

KW - fluorescence

KW - optical isomers

KW - peptides

KW - radical-ions

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85148935524&origin=inward&txGid=e7ba15ab5e69ff36880bf5d2a45e380f

UR - https://www.mendeley.com/catalogue/f82ac042-218a-300c-9c00-c287cd5f3fdf/

U2 - 10.3390/ijms24043331

DO - 10.3390/ijms24043331

M3 - Article

C2 - 36834744

VL - 24

JO - International Journal of Molecular Sciences

JF - International Journal of Molecular Sciences

SN - 1661-6596

IS - 4

M1 - 3331

ER -