Raman Spectra of Amino Acids and Related Substances III. Ionization and Methylation of the Amino Group

1937 ◽  
Vol 5 (4) ◽  
pp. 225-237 ◽  
Author(s):  
John T. Edsall
Keyword(s):  
Amino Acids ◽  
Raman Spectra ◽  
Amino Group ◽  
Related Substances

scholarly journals THERMODYNAMIC PROPERTIES OF SOLUTIONS OF AMINO ACIDS AND RELATED SUBSTANCES

1942 ◽  
Vol 144 (3) ◽  
pp. 737-745
Author(s):  
Paul K. Smith ◽  
Alice T. Gorham ◽  
Elizabeth R.B. Smith
Keyword(s):  
Amino Acids ◽  
Thermodynamic Properties ◽  
Related Substances

Special transport and neurological significance of two amino acids in a configuration conventionally designated as D.

1994 ◽  
Vol 196 (1) ◽  
pp. 297-305 ◽  
Author(s):  
H N Christensen ◽  
A A Greene ◽  
D K Kakuda ◽  
C L MacLeod
Keyword(s):  
Amino Acids ◽  
Receptor Site ◽  
Amino Group ◽  
Carboxylate Group ◽  
Gamma Aminobutyric Acid ◽  
Imino Group ◽  
Group A ◽  
The Central Nervous System ◽  
Lower Homolog ◽  
Alpha Amino Acid

We point out an ability of certain amino acids to be recognized at a biological receptor site as though their amino group bore, instead of an alpha relationship to a carboxylate group, a beta, gamma or delta relationship to the same or a second carboxylate group. For aspartate, the unbalanced position of its amino group between a pair of carboxylates allows its occasional biorecognition as a beta-rather than as an alpha-amino acid, whereas for proline and its homologs, their cyclic arrangement may allow the imino group, without its being replicated, to be sensed analogously as falling at either of two distances from the single carboxylate group. The greater separation might allow proline to be seen as biologically analogous to gamma-aminobutyric acid. This more remote positioning of the imino group would allow the D-form of both amino acids to present its amino group in the orientation characteristic of the natural L-form. The dual modes of recognition should accordingly be signalled by what appears to be low stereospecificity, actually due to a distinction in the enantiorecognition of the two isomers. Competing recognition for transport between their respective D- and L-forms, although it does not prove that phenomenon, has been shown for proline and, significantly, even more strongly for its lower homolog, 2-azetidine carboxylate. Such indications have so far revealed themselves rather inconspicuously for the central nervous system binding of proline, reviewed here as a possible feature of a role suspected for proline in neurotransmission.

scholarly journals Комбинационное рассеяние света в хирально чистых и рацемической фазах поликристаллов триптофана и тирозина

2019 ◽  
Vol 127 (10) ◽  
pp. 541
Author(s):  
В.С. Горелик ◽  
М.Ф. Умаров ◽  
Ю.П. Войнов
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Raman Spectra ◽  
Spectral Range ◽  
Phase State ◽  
Source Parameters ◽  
Low Frequency ◽  
Aromatic Amino Acids ◽  
Chiral Phase ◽  
Left Handed

AbstractRaman spectra of tryptophan and tyrosine polycrystals have been analyzed in a wide spectral range by fiber-optic spectroscopy. The Raman spectra have been recorded with a BWS465-785H spectrometer in the spectral range of 0–2700 cm^–1 using a 785-nm cw laser as an excitation source. Parameters of the Raman spectra are compared for three crystalline phase modifications of aromatic amino acids: left-handed, right-handed, and racemic phase. The presence of strong Raman satellites, the characteristics of which change depending on the type of the chiral phase state of amino acid, is found in the low-frequency Raman spectra of tryptophan and tyrosine amino acid lattices. The results obtained can be used for monitoring the chiral purity of bioactive preparations containing amino acids.

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