UV Absorption Characteristics of N-Acetyl Methyl Esters of the Aromatic Amino Acids, Cystine and of N-Acetylcysteine

2010 ◽  
pp. 81-81
Keyword(s):  
Amino Acids ◽  
Methyl Esters ◽  
Aromatic Amino Acids ◽  
Uv Absorption ◽  
Absorption Characteristics

scholarly journals Canine Plasminogen: Spectral Responses to Changes in 6-Aminohexanoate and Temperature

2007 ◽  
Vol 2 ◽  
pp. 117739010700200 ◽  
Author(s):  
Jack A. Kornblatt ◽  
Tanya A. Barretto ◽  
Ketevan Chigogidze ◽  
Bahati Chirwa
Keyword(s):  
Amino Acids ◽  
Absorption Spectrum ◽  
Aromatic Amino Acids ◽  
The Other ◽  
Uv Absorption ◽  
Derivative Spectra ◽  
Increasing Temperature ◽  
A Site ◽  
Spectral Responses ◽  
Uv Absorption Spectrum

We studied the near UV absorption spectrum of canine plasminogen. There are 19 tryptophans, 19 phenylalanines and 34 tyrosines in the protein. 4th derivative spectra optimized for either tryptophan or tyrosine give a measure of the polarity of the environments of these two aromatic amino acids. Plasminogen at temperatures between 0°C and 37°C exists as a mixture of four conformations: closed-relaxed, open-relaxed, closed-compact, and open-compact. The closed to open transition is driven by addition of ligand to a site on the protein. The relaxed to compact transition is driven by increasing temperature from 0°C to above 15-20°C. When the conformation of plasminogen is mainly closed-relaxed, the 4th derivative spectra suggest that the average tryptophan environment is similar to a solution of 20% methanol at the same temperature. Under the same conditions, 4th derivative spectra suggest that the average tyrosine environment is similar to water. These apparent polarities change as the plasminogen is forced to assume the other conformations. We try to rationalize the information based on the known portions of the plasminogen structure.

Simultaneous determination of aromatic amino acids in human blood plasma by capillary electrophoresis with UV-absorption detection

2015 ◽  
Vol 38 (10) ◽  
pp. 1794-1799 ◽  
Author(s):  
Mauro Forteschi ◽  
Salvatore Sotgia ◽  
Stefano Assaretti ◽  
Dionigia Arru ◽  
Debora Cambedda ◽  
...  
Keyword(s):  
Amino Acids ◽  
Capillary Electrophoresis ◽  
Blood Plasma ◽  
Simultaneous Determination ◽  
Human Blood ◽  
Aromatic Amino Acids ◽  
Uv Absorption ◽  
Human Blood Plasma

The Efficient Preparation of Radiolabeled Aromatic Amino Acids via Cu-Mediated Radiofluorination using Ni-complexes

2019 ◽  
Author(s):  
A Craig ◽  
N Kolks ◽  
E Urusova ◽  
BD Zlatopolskiy ◽  
B Neumaier
Keyword(s):  
Amino Acids ◽  
Aromatic Amino Acids

Long term dietary intake of aromatic amino acids are associated with leptin gene expression in adipose tissues of non-diabetic adults

2018 ◽  
Author(s):  
Golaleh Asghari ◽  
Emad Yuzbashian ◽  
Maryam Zarkesh ◽  
Parvin Mirmiran ◽  
Mehdi Hedayati ◽  
...  
Keyword(s):  
Gene Expression ◽  
Amino Acids ◽  
Dietary Intake ◽  
Aromatic Amino Acids ◽  
Adipose Tissues

Single Amino Acid Based Self-Assemblies of Cysteine and Methionine

2018 ◽  
Author(s):  
Nidhi Gour ◽  
Bharti Koshti ◽  
Chandra Kanth P. ◽  
Dhruvi Shah ◽  
Vivek Shinh Kshatriya ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Self Assembly ◽  
Aromatic Amino Acids ◽  
Neutral Condition ◽  
Single Amino Acid ◽  
Binding Assays ◽  
Human Neuroblastoma ◽  
Cytotoxicity Assays ◽  
First Time

We report for the very first time self-assembly of Cysteine and Methionine to discrenible strucutres under neutral condition. To get insights into the structure formation, thioflavin T and Congo red binding assays were done which revealed that aggregates may not have amyloid like characteristics. The nature of interactions which lead to such self-assemblies was purported by coincubating assemblies in urea and mercaptoethanol. Further interaction of aggregates with short amyloidogenic dipeptide diphenylalanine (FF) was assessed. While cysteine aggregates completely disrupted FF fibres, methionine albeit triggered fibrillation. The cytotoxicity assays of cysteine and methionine structures were performed on Human Neuroblastoma IMR-32 cells which suggested that aggregates are not cytotoxic in nature and thus, may not have amyloid like etiology. The results presented in the manuscript are striking, since to the best of our knowledge,this is the first report which demonstrates that even non-aromatic amino acids (cysteine and methionine) can undergo spontaneous self-assembly to form ordered aggregates.

Atypical amino acids inhibit histidine, valine, or lysine transport into rat brain

1983 ◽  
Vol 245 (4) ◽  
pp. R556-R563 ◽  
Author(s):  
J. K. Tews ◽  
A. E. Harper
Keyword(s):  
Amino Acids ◽  
Rat Brain ◽  
Blood Brain Barrier ◽  
Brain Slices ◽  
Aromatic Amino Acids ◽  
Brain Barrier ◽  
Basic Amino Acids ◽  
Large Neutral Amino Acids ◽  
Neutral Amino Acids ◽  
Single Meal

Transport of histidine, valine, or lysine into rat brain slices and across the blood-brain barrier (BBB) was determined in the presence of atypical nonprotein amino acids. Competitors of histidine and valine transport in slices were large neutral amino acids including norleucine, norvaline, alpha-aminooctanoate, beta-methylphenylalanine, and alpha-aminophenylacetate. Less effective were aromatic amino acids with ring substituents; ineffective were basic amino acids and omega-amino isomers of norleucine and aminooctanoate. Lysine transport was moderately depressed by homoarginine or ornithine plus arginine; large neutral amino acids were also similarly inhibitory. Histidine or valine transport across the BBB was also strongly inhibited by large neutral amino acids that were the most effective competitors in the slices (norvaline, norleucine, alpha-aminooctanoate, and alpha-aminophenylacetate); homoarginine and 8-aminooctanoate were ineffective. Homoarginine, ornithine, and arginine almost completely blocked lysine transport, but the large neutral amino acids were barely inhibitory. When rats were fed a single meal containing individual atypical large neutral amino acids or homoarginine, brain pools of certain large neutral amino acids or of arginine and lysine, respectively, were depleted.

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