Characteristic oxygen <i>K</i>-edge circular dichroism spectra of amino acid films by improved measurement technique

Izumi, Yudai; Tanabe, Maiko; Imazu, Akiko; Mimoto, Aki; Tanaka, Masahito; Agui, Akane; Matsuki, Takayuki; Nakagawa, Kazumichi

doi:10.1063/1.4790599

Cited by 13 publications

(11 citation statements)

References 46 publications

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“…However, slight differences in relative peak intensities were observed; they might have emerged due to the difference between the film and pellets, i.e., the thickness and density of the thin films are different from those of the pellets. In previous circular dichroism (CD) experiments of amino acids in the vacuum-UV and soft X-ray regions by Izumi et al., 5,6 the same evaporation method as ours has been adopted, and they have obtained spectra that are consistent with powder samples. These results also suggest that the thermal degradation can be ignored.…”

Section: Resultsmentioning

confidence: 90%

“…Another method that can reveal the chirality is the circular dichroism spectroscopy for the vacuum-ultraviolet (UV) and soft X-ray spectral regions. 5,6 However, as these methods require a very high sensitivity owing to the very low dichroism signal, the concentration of D-amino acid molecules and their spatial distribution cannot be measured. To detect the spatial distribution of D-amino acids gives us the information of the deformation position of peptides and proteins owing to racemization, which is a sign of aging diseases.…”

Section: Introductionmentioning

confidence: 99%

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Infrared Evaluation of Enantiometric Amount and Application to Racemization at the Interface Between L- and D-Alanine

et al. 2018

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Amino acids, except for glycine, have two types of molecular structures, L- and D-forms, which are enantiomers. As the L- and D-form molecules have identical chemical and physical properties, they cannot be easily identified by conventional methods. In this study, we found that the amount and the spatial distribution of D-enantiomers in an L-alanine (CHCH(COOH)NH) matrix in evaporated thin films, which is one of amino acid molecules, can be evaluated quantitatively using an infrared micro spectroscopy with synchrotron radiation. This method was applied to the evaluation of the volume fraction of a racemic component appearing at the interface between L- and D-alanine thin films.

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Section: Resultsmentioning

confidence: 90%

Section: Introductionmentioning

confidence: 99%

Infrared Evaluation of Enantiometric Amount and Application to Racemization at the Interface Between L- and D-Alanine

et al. 2018

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“…Since the oscillator strength distributions are uncharacterized in this region, it is also an important future work to determine them experimentally although they can be roughly estimated from the number of atoms comprising the molecules [25]. In such experiments, the method described in this work is applicable by replacing the collodion films for silicon nitride [26,27] or silicon carbide films [28]. By combining such future works, more precise estimations of the interaction between DNA bases and IRs or photons can be achieved.…”

Section: Resultsmentioning

confidence: 99%

Optical Absorption Cross-Section of DNA Bases—Thymine and Guanine—in the Energy Region from 3.1 to 250 eV (5–400 nm)

Koswattage

Izumi

Nakagawa

2020

QuBS

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(1) Background: Optical absorption cross-section—the absolute absorption intensity specific to each molecule—of nucleic acid bases enables us to estimate the reaction yields of DNA lesions induced by the exposure to not only photons but also ionizing radiations. However, it was unknown in the energy region exceeding ~10 eV (wavelength < ~120 nm). (2) Methods: Thin films of DNA bases—thymine and guanine—were prepared using a vacuum sublimation technique. Absorption spectra of these films were measured in the energy region from 3.1 to 250 eV (5–400 nm) at the synchrotron radiation facility UVSOR. (3) Results: The absorption spectra of both bases exhibited prominent absorption peaks around 20 eV and smaller peaks in the energy region below 10 eV. The determined optical oscillator strength distribution was verified to be reasonable based on the Thomas–Reiche–Kuhn oscillator strength sum rule. (4) Conclusion: Most of the oscillator strength distribution was positioned in the measured energy region, and therefore the absorption spectra significantly contributed to the quantitative study for the photo and radiation-chemical reactions of DNA.

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“…At most synchrotron radiation facilities, the polarization of the light beam is converted to R-and L-CPL using a photoelastic modulator (PEM) [75]. Recently, the use of an Onuki-type crossed undulator has further extended the accessible CD range from 140 to 120 nm [79,80] and even to the soft x-ray region by utilizing a sophisticated helicity switching system [81,82].…”

Section: Theoretical Background For Absolute Asymmetric Photolysis By Cplmentioning

confidence: 99%

d -Amino acids in molecular evolution in space – Absolute asymmetric photolysis and synthesis of amino acids by circularly polarized light

Sugahara

Meinert

Nahon

et al. 2018

Biochimica et Biophysica Acta (BBA) - Proteins and Proteomics

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Living organisms on the Earth almost exclusively use l-amino acids for the molecular architecture of proteins. The biological occurrence of d-amino acids is rare, although their functions in various organisms are being gradually understood. A possible explanation for the origin of biomolecular homochirality is the delivery of enantioenriched molecules via extraterrestrial bodies, such as asteroids and comets on early Earth. For the asymmetric formation of amino acids and their precursor molecules in interstellar environments, the interaction with circularly polarized photons is considered to have played a potential role in causing chiral asymmetry. In this review, we summarize recent progress in the investigation of chirality transfer from chiral photons to amino acids involving the two major processes of asymmetric photolysis and asymmetric synthesis. We will discuss analytical data on cometary and meteoritic amino acids and their potential impact delivery to the early Earth. The ongoing and future ambitious space missions, Hayabusa2, OSIRIS-REx, ExoMars 2020, and MMX, are scheduled to provide new insights into the chirality of extraterrestrial organic molecules and their potential relation to the terrestrial homochirality. This article is part of a Special Issue entitled: d-Amino acids: biology in the mirror, edited by Dr. Loredano Pollegioni, Dr. Jean-Pierre Mothet and Dr. Molla Gianluca.

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Characteristic oxygen K-edge circular dichroism spectra of amino acid films by improved measurement technique

Cited by 13 publications

References 46 publications

Infrared Evaluation of Enantiometric Amount and Application to Racemization at the Interface Between L- and D-Alanine

Infrared Evaluation of Enantiometric Amount and Application to Racemization at the Interface Between L- and D-Alanine

Optical Absorption Cross-Section of DNA Bases—Thymine and Guanine—in the Energy Region from 3.1 to 250 eV (5–400 nm)

d -Amino acids in molecular evolution in space – Absolute asymmetric photolysis and synthesis of amino acids by circularly polarized light

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