scholarly journals Prebiotic synthesis of aminooxazoline-5′-phosphates in water by oxidative phosphorylation

2017 ◽  
Vol 53 (36) ◽  
pp. 4919-4921 ◽  
Author(s):  
C. Fernández-García ◽  
N. M. Grefenstette ◽  
M. W. Powner
Keyword(s):  
Amino Acids ◽  
Oxidative Phosphorylation ◽  
Prebiotic Synthesis ◽  
Strecker Synthesis ◽  
Novel Strategy

A novel strategy for aminooxazoline-5′-phosphate synthesis in water from prebiotic feedstocks, which is generationally linked to Strecker synthesis of proteinogenic amino acids.

scholarly journals Lactate oxidative phosphorylation by annulus fibrosus cells: evidence for lactate-dependent metabolic symbiosis in intervertebral discs

2021 ◽  
Vol 23 (1) ◽  
Author(s):  
Dong Wang ◽  
Robert Hartman ◽  
Chao Han ◽  
Chao-ming Zhou ◽  
Brandon Couch ◽  
...  
Keyword(s):  
Amino Acids ◽  
Lactic Acid ◽  
Oxidative Phosphorylation ◽  
Intervertebral Disc ◽  
Annulus Fibrosus ◽  
Tca Cycle ◽  
Heavy Isotope ◽  
In Vivo Models ◽  
Disc Tissue ◽  
Tca Cycle Intermediates

Abstract Background Intervertebral disc degeneration contributes to low back pain. The avascular intervertebral disc consists of a central hypoxic nucleus pulpous (NP) surrounded by the more oxygenated annulus fibrosus (AF). Lactic acid, an abundant end-product of NP glycolysis, has long been viewed as a harmful waste that acidifies disc tissue and decreases cell viability and function. As lactic acid is readily converted into lactate in disc tissue, the objective of this study was to determine whether lactate could be used by AF cells as a carbon source rather than being removed from disc tissue as a waste byproduct. Methods Import and conversion of lactate to tricarboxylic acid (TCA) cycle intermediates and amino acids in rabbit AF cells were measured by heavy-isotope (13C-lactate) tracing experiments using mass spectrometry. Levels of protein expression of lactate converting enzymes, lactate importer and exporter in NP and AF tissues were quantified by Western blots. Effects of lactate on proteoglycan (35S-sulfate) and collagen (3H-proline) matrix protein synthesis and oxidative phosphorylation (Seahorse XFe96 Extracellular Flux Analyzer) in AF cells were assessed. Results Heavy-isotope tracing experiments revealed that AF cells imported and converted lactate into TCA cycle intermediates and amino acids using in vitro cell culture and in vivo models. Addition of exogenous lactate (4 mM) in culture media induced expression of the lactate importer MCT1 and increased oxygen consumption rate by 50%, mitochondrial ATP-linked respiration by 30%, and collagen synthesis by 50% in AF cell cultures grown under physiologic oxygen (2-5% O2) and glucose concentration (1-5 mM). AF tissue highly expresses MCT1, LDH-H, an enzyme that preferentially converts lactate to pyruvate, and PDH, an enzyme that converts pyruvate to acetyl-coA. In contrast, NP tissue highly expresses MCT4, a lactate exporter, and LDH-M, an enzyme that preferentially converts pyruvate to lactate. Conclusions These findings support disc lactate-dependent metabolic symbiosis in which lactate produced by the hypoxic, glycolytic NP cells is utilized by the more oxygenated AF cells via oxidative phosphorylation for energy and matrix production, thus shifting the current research paradigm of viewing disc lactate as a waste product to considering it as an important biofuel. These scientifically impactful results suggest novel therapeutic targets in disc metabolism and degeneration.

Prebiotic synthesis of carboxylic acids, amino acids and nucleic acid bases from formamide under photochemical conditions⋆

2017 ◽  
Vol 132 (7) ◽  
Author(s):  
Lorenzo Botta ◽  
Bruno Mattia Bizzarri ◽  
Davide Piccinino ◽  
Teresa Fornaro ◽  
John Robert Brucato ◽  
...  
Keyword(s):  
Amino Acids ◽  
Nucleic Acid ◽  
Carboxylic Acids ◽  
Prebiotic Synthesis ◽  
Nucleic Acid Bases

One-Pot Synthesis of α-Amino Acids from Imines through CO2 Incorporation: An Alternative Method for Strecker Synthesis

2011 ◽  
Vol 123 (6) ◽  
pp. 1429-1432 ◽  
Author(s):  
Tsuyoshi Mita ◽  
Jianyang Chen ◽  
Masumi Sugawara ◽  
Yoshihiro Sato
Keyword(s):  
Amino Acids ◽  
One Pot ◽  
One Pot Synthesis ◽  
Alternative Method ◽  
Strecker Synthesis

Asymmetric Synthesis of α-Amino-acids by the Strecker Synthesis

Nature ◽  
1963 ◽  
Vol 200 (4912) ◽  
pp. 1201-1201 ◽  
Author(s):  
KAORU HARADA
Keyword(s):  
Amino Acids ◽  
Asymmetric Synthesis ◽  
Strecker Synthesis
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