Origin of asymmetry in biomolecules

Garay, A. S.; Keszthelyi, L.; Demeter, I.; Hraskó, P.

doi:10.1038/250332a0

Cited by 46 publications

(17 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…1) is described. The result here may be also considered a followup study and extension of early work by Garay et al [6], Rich [8], and others investigating positron annihilation in L-and D-amino acids over the years.…”

Section: Introductionsupporting

confidence: 63%

“…The history of positron experiments with asymmetric matter caught our attention as being a significant research area despite small, ambiguous, or negative results observed over the last four decades [5][6][7][8][9][10][11]. This interest extends to the other beta particle, the electron, and polarized electron experiments with asymmetric matter that have been recently appearing in the literature [12][13][14].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Positron Annihilation Lifetime Analysis of Left- and Right-Handed Alanine Single Crystals

Eren

et al. 2017

Acta Phys. Pol. A

View full text Add to dashboard Cite

Studies of the interaction of polarized light or particles (including electrons, e − , or positrons, e + ) with asymmetric forms of matter has been of interest to scientists since the discovery of chirality and the subsequent development of particle physics. Researchers have been interested in e + interactions with chiral molecules for decades, but with mixed and indecisive results. After reviewing the field, we speculated that the e + or positronium (Ps) might interact differently with chiral pairs of large single crystals, i.e., the left-handed or right-handed asymmetric forms of the crystals -and subsequently observed significant differences in "free positron" annihilation and intensities in the evaluation of left-handed or right-handed quartz single crystals. This result may be understood to be a "particle stereorecognition" phenomenon. To extend this line of inquiry we crystallized mm scale L-or D-alanine crystals and performed positron annihilation lifetime spectroscopy measurements using a 22 Na positron source. Alanine crystals were obtained via slow evaporation of water in a Dewar, or from water/acetone solvent in a temperature-controlled environment. These methods resulted in small (≈ 0.5 cm/side) or large (≥ 1.0 cm/side) crystals, respectively. While some intensity (I2) results from left-handed and right-handed crystals varied in positron annihilation lifetime spectroscopy analysis, the errors associated with the measurements do not indicate a stereorecognition of alanine via positron interactions.

show abstract

Section: Introductionsupporting

confidence: 63%

Section: Introductionmentioning

confidence: 99%

Positron Annihilation Lifetime Analysis of Left- and Right-Handed Alanine Single Crystals

Eren

et al. 2017

Acta Phys. Pol. A

View full text Add to dashboard Cite

show abstract

“…Indeed, a large observed effect involving asymmetric formation of triplet positronium in L-amino acids versus D-amino acids [2] was originally interpreted as possibly being due to positron helicity. However, that interpretation was later shown to be invalid [3] and in fact the original effect could not be reproduced [4].…”

Section: Introductionmentioning

confidence: 99%

Positron scattering from chiral enantiomers

et al. 2012

View full text Add to dashboard Cite

We report on total cross section measurements for positron scattering from the chiral enantiomers (+)-methyl (R)-2-chloropropionate and (-)-methyl (S)-2-chloropropionate. The energy range of the present study was 0.1-50 eV, while the energy resolution of our incident positron beam was ∼0.25 eV (FWHM). As positrons emanating from β decay in radioactive nuclei have a high degree of spin polarization, which persists after moderation, we were particularly interested in probing whether the positron helicity differentiates between the measured total cross sections of the two enantiomers. No major differences were, however, observed. Finally, quantum chemical calculations, using the density functional theory based B3LYP-DGTZVP model within the GAUSSIAN 09 package, were performed as a part of this work in order to assist us in interpreting some aspects of our data.

show abstract

“…Which one of the specific suggested mechanisms takes place [10,12] as well as the careful examination relating the same magnitude of the induced effect to be expected is constituting now a problem for our further investigation in relation to the results of the present paper. Which one of the specific suggested mechanisms takes place [10,12] as well as the careful examination relating the same magnitude of the induced effect to be expected is constituting now a problem for our further investigation in relation to the results of the present paper.…”

Section: Resultsmentioning

confidence: 79%

“…On a theoretical ground the examination of the possible [10,12] mechanisms involved in this phenomenon [8,17] continues to attract interest since leptons as electrons (positrons) from a beta emitter are polarized with left-handed negative (right-handed positive) helicity equal numerically to the ratio of the electron velocity to the velocity of light and, in addition, almost all known beta-active elements are found in nature to be electron and not positron emitters.…”

Section: Introductionmentioning

confidence: 99%