TY - JOUR

T1 - Stereoselectivity of electron and energy transfer in the quenching of (S/R)-ketoprofen-(S)-tryptophan dyad excited state

AU - Ageeva, Aleksandra A.

AU - Babenko, Simon V.

AU - Magin, Ilya M.

AU - Plyusnin, Victor F.

AU - Kuznetsova, Polina S.

AU - Stepanov, Alexander A.

AU - Vasilevsky, Sergey F.

AU - Polyakov, Nikolay E.

AU - Doktorov, Alexander B.

AU - Leshina, Tatyana V.

N1 - This research was funded by RUSSIAN SCIENCE FOUNDATION, grant number 18-13-00047. Time-resolved luminescence experiments were funded by RUSSIAN SCIENCE FOUNDATION, grant number 18-13-00246.

PY - 2020/8/1

Y1 - 2020/8/1

N2 - Photoinduced elementary processes in chiral linked systems, consisting of drugs and tryptophan (Trp) residues, attract considerable attention due to several aspects. First of all, these are models that allow one to trace the full and partial charge transfer underlying the binding of drugs to enzymes and receptors. On the other hand, Trp fluorescence is widely used to establish the structure and conformational mobility of proteins due to its high sensitivity to the microenvironment. Therefore, the study of mechanisms of Trp fluorescence quenching in various systems has both fundamental and practical interest. An analysis of the photo-chemically induced dynamic nuclear polarization (CIDNP) and Trp fluorescence quenching in (R/S)-ketoprofen-(S)-tryptophan ((S/R)-KP-(S)-Trp) dyad carried out in this work allowed us to trace the intramolecular reversible electron transfer (ET) and obtain evidence in favor of the resonance energy transfer (RET). The fraction of dyad’s singlet excited state, quenched via ET, was shown to be 7.5 times greater for the (S,S)-diastereomer than for the (R,S) analog. At the same time, the ratio of the fluorescence quantum yields shows that quenching effectiveness of (S,S)-diastereomer to be 5.4 times lower than for the (R,S) analog. It means that the main mechanism of Trp fluorescence quenching in (S/R)-KP-(S)-Trp dyad is RET.

AB - Photoinduced elementary processes in chiral linked systems, consisting of drugs and tryptophan (Trp) residues, attract considerable attention due to several aspects. First of all, these are models that allow one to trace the full and partial charge transfer underlying the binding of drugs to enzymes and receptors. On the other hand, Trp fluorescence is widely used to establish the structure and conformational mobility of proteins due to its high sensitivity to the microenvironment. Therefore, the study of mechanisms of Trp fluorescence quenching in various systems has both fundamental and practical interest. An analysis of the photo-chemically induced dynamic nuclear polarization (CIDNP) and Trp fluorescence quenching in (R/S)-ketoprofen-(S)-tryptophan ((S/R)-KP-(S)-Trp) dyad carried out in this work allowed us to trace the intramolecular reversible electron transfer (ET) and obtain evidence in favor of the resonance energy transfer (RET). The fraction of dyad’s singlet excited state, quenched via ET, was shown to be 7.5 times greater for the (S,S)-diastereomer than for the (R,S) analog. At the same time, the ratio of the fluorescence quantum yields shows that quenching effectiveness of (S,S)-diastereomer to be 5.4 times lower than for the (R,S) analog. It means that the main mechanism of Trp fluorescence quenching in (S/R)-KP-(S)-Trp dyad is RET.

KW - Chiral linked systems

KW - Diastereomers

KW - Electron transfer

KW - Fluorescence

KW - Resonance energy transfer

KW - Stereoselectivity

UR - http://www.scopus.com/inward/record.url?scp=85088883452&partnerID=8YFLogxK

U2 - 10.3390/ijms21155370

DO - 10.3390/ijms21155370

M3 - Article

C2 - 32731624

AN - SCOPUS:85088883452

VL - 21

SP - 1

EP - 15

JO - International Journal of Molecular Sciences

JF - International Journal of Molecular Sciences

SN - 1661-6596

IS - 15

M1 - 5370

ER -