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A S Garay

Publications and source records attributed to A S Garay.

13 recordsLinked to original sources
PubMed1987

Differential interactions of beta particles with liquid enantiomers and internal timing of chiral molecules.

The Cerenkov and liquid scintillation technique was applied to detect differential interactions between beta particles and chiral molecules. The highly helical beta emitting 32P and the barely helical beta emitting 3H were dissolved in the liquid enantiomers of 2-phenylbutyric acid. The interactions of the beta particles with the enantiomers were compared. Differential interactions were observed in case of 32P. The stopping power of R enantiomers was greater than that of the S enantiomer. The apparent decay of 32P was faster in the S enantiomer than in the R enantiomer. It is not clear whether this is due to some mistake in measurement or reflects the postulated difference of internal timing of the two enantiomers. Since, in spite of all efforts, contamination could not totally be excluded and data are significant only to one sigma, results must be considered preliminary. The method, however, seems to be more sensitive than all previously used methods. The differential effect was always in the same direction in at least 5 replicas.

Beta Particles↗
PubMed1986

Rhizobins, a group of peptides in the free-amino-Acid pool of the soybean-Rhizobium system.

Free-living Rhizobium (according to Bergey's Manual of Systematic Bacteriology, [1984, The Williams & Wilkins Co., Baltimore], Bradyrhizobium) japonicum was found to release a peptide into the nutrient media. Soybean nodules contained this peptide and exuded it into the soil. The name "rhizobin A" is suggested for this peptide. Nodules also contained another peptide, rhizobin B, as well as an unidentified, ninhydrin-positive compound, rhizobin C. The three peptides were confined to the free-amino-acid pool of the soluble fraction and eluted consecutively from a cation-exchange column. Rhizobin A was isolated in a highly purified form; its molecular mass was approximately 1,600 daltons as determined by Sephadex gel filtration and mass spectrometry. The amino-acid composition could be determined only approximately, because a long time was necessary for acid hydrolysis, possibly due to unusual linkages. The rhizobin concentration in soybean nodules continually increased during 50 days of growth, from 2 to approximately 400 mug/g (fresh weight). When combined nitrogen was added to nodulated soybean and subsequently removed, nitrogenase activity, nodulation, and nodule growth first decreased and then recovered. The relative amount of rhizobin A followed a similar pattern. Rhizobins were not detected in the roots, stems, and leaves of nodulated soybean plants. They were present in Lupinus nodules, but absent in alder nodules.

Journal Article↗
PubMed1978

Superweak interactions and the biological time direction.

A hypothesis is proposed in qualitative terms, according to which left helical electrons in chiral molecules, and right helical electrons in oppositely chiral molecules have different internal timings. The basis of this hypothesis stems from two facts: (1) It has been observed that the decay processes caused by superweak interactions go slower if left helical electrons are produced compared to decay processes in which right helical positrons are produced. (2) The excited states of D and L molecules are not only parity transformed but time reversed pairs as well. Re-evaluation of many data makes the hypothesis likely. The significance of this hypothesis in the origin and evolution of life is apparent since life and evolution as a whole have a special time direction.

Biophysical Phenomena↗
PubMed1975

Neutral currents in weak interactions and molecular asymmetry.

Weak interactions are parity violating forces, i.e. they differentiate between mirror images. Therefore it is a very attractive hypothesis to invoke weak interactions in explaining the origin of molecular asymmetry. It is, however, not clear whether weak interactions may operate between electrons and/or between electrons and protons? For these types of interactions so called neutral currents are needed. Recent experiments with muon neutrinos at CERN gave some evidence for the existence of neutral currents. Thus we may suppose that parity violating forces are active in molecules. In the first part of this paper a very elementary theory of weak interactions is outlined with special reference to the discovery of neutral currents. In the second part we show how weak interactions may differentiate between mirror image molecules. The asymmetrically distributed static charges in chiral molecules represent a helical potential field. This potential field may exert an effect on the orbital electrons and therefore coupling of spins and momenta occurs. Thus the enantiomers are parity transformed images not only as geometrical bodies, but their orbital electrons are parity transformed too as "a helical electron gas". Weak interactions will differentiate between L and D forms because their orbital electrons have a nonzero spin polarization with respect to their velocity.

Electrochemistry↗
PubMed1973

Circular dichroism spectra of granal and agranal chloroplasts of maize.

Granum-containing chloroplasts from mesophyll cells of maize (Zea mays L. var. MV 861) leaves exhibited circular dichroism spectra with a large double signal; peaks at 696 nm (+) and 680 nm (-). In the circular dichroism spectra obtained with agranal chloroplasts of bundle sheath cells, this large double signal is absent. Separation of grana lamellae, in a medium of low salt concentration and in KSCN solution, resulted only in a slight decrease of the amplitude, while upon treatment with digitonin the large double signal disappeared. A negative signal of the chlorophyll b peak at 654 nm was observed in the case of both granal and agranal chloroplasts, and it was not affected either by low salt or by digitonin treatment. A positive peak at about 515 nm was higher in granal than in agranal chloroplasts.

Journal Article↗