Tissue sulfhydryl groups

The Wealth of India. Raw Materials

The pentose phosphate pathway (PPP) is a fundamental component of cellular metabolism. The PPP is important to maintain carbon homoeostasis, to provide precursors for nucleotide and amino acid biosynthesis, to provide reducing molecules for anabolism, and to defeat oxidative stress. The PPP shares reactions with the Entner-Doudoroff pathway and Calvin cycle and divides into an oxidative and non-oxidative branch. The oxidative branch is highly active in most eukaryotes and converts glucose 6-phosphate into carbon dioxide, ribulose 5-phosphate and NADPH. The latter function is critical to maintain redox balance under stress situations, when cells proliferate rapidly, in ageing, and for the 'Warburg effect' of cancer cells. The non-oxidative branch instead is virtually ubiquitous, and metabolizes the glycolytic intermediates fructose 6-phosphate and glyceraldehyde 3-phosphate as well as sedoheptulose sugars, yielding ribose 5-phosphate for the synthesis of nucleic acids and sugar phosphate precursors for the synthesis of amino acids. Whereas the oxidative PPP is considered unidirectional, the non-oxidative branch can supply glycolysis with intermediates derived from ribose 5-phosphate and vice versa, depending on the biochemical demand. These functions require dynamic regulation of the PPP pathway that is achieved through hierarchical interactions between transcriptome, proteome and metabolome. Consequently, the biochemistry and regulation of this pathway, while still unresolved in many cases, are archetypal for the dynamics of the metabolic network of the cell. In this comprehensive article we review seminal work that led to the discovery and description of the pathway that date back now for 80 years, and address recent results about genetic and metabolic mechanisms that regulate its activity. These biochemical principles are discussed in the context of PPP deficiencies causing metabolic disease and the role of this pathway in biotechnology, bacterial and parasite infections, neurons, stem cell potency and cancer metabolism.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/brv.12140

The return of metabolism: biochemistry and physiology of the pentose phosphate pathway

Flow cytometry of heated sperm nuclei revealed a significant decrease in resistance to in situ denaturation of spermatozoal DNA in samples from bulls, mice, and humans of low or questionable fertility when compared with others of high fertility. Since thermal denaturation of DNA in situ depends on chromatin structure, it is assumed that changes in sperm chromatin conformation may be related to the diminished fertility. Flow cytometry of heated sperm nuclei may provide a new and independent determinant of male fertility.

https://science.sciencemag.org/content/sci/210/4474/1131.full.pdf

Relation of mammalian sperm chromatin heterogeneity to fertility.

PERSPECTIVES AND SUMMARY 1006 INTRODUCTION 1007 PROLINE 1008 Proline Biosynthesis: The Glutamate Pathway 1008 Proline Biosynthesis: The Om Pathway 1015 Proline Degradation: The P5C Pathway 1018 Proline Degradation: Reguiation 1020 Proline Degradation: Other Pathways 1023 4-HYDROXYPROLlNE 1024 Natural Occurrence 1024 Metabolism General Features 1025 Catabolism of Free 4-Hyp 1034 3-HYDROXYPROLINE 1041 Metabolism 1042 3,4-DIHYDROXYPROLINE 1044

Metabolism of Proline and the Hydroxyprolines

IN a recent publication1 from this laboratory, a method for the separation of amino-acids by circular paper chromatography was outlined. The present communication describes a new technique, which permits the identification of amino-acids by reference to the chromatogram of the known amino-acids run on the same paper.

A Technique for the Identification of Amino-Acids separated by Circular Paper Chromatography

/pdf/the-isolation-of-allohydroxy-l-proline-from-sandal-santalum-kpukwrtk8t.pdf

The isolation of allohydroxy-L-proline from sandal (Santalum album L.).

The occurrence of at least four non-reducing oligosaccharides has been observed in pulses. Three of the saccharides have been separated from resting seeds of green gram and have been characterized ...

Sugar in pulses.

RECENTLY, the application of paper chromatography to the study of transamination reactions has been reported by several workers. The method adopted by Fincham1 is based on the visual comparison of the spots and as such it is only roughly quantitative. Tulpule and Patwardhan2 reported a method based on conversion of α-ketoglutaric acid and pyruvic acid to the respective dinitrophenyl-hydrazones and estimating them colorimetrically after paper chromatographic separation. This method, even though claimed to be accurate, is obviously time-consuming and tedious. While our work on transaminating systems in Indian pulses was in progress, Awapara's paper3 appeared in which the distribution of transaminases in rat organs was followed by using unidimensional paper chromatography.

A Simple Paper Chromatographic Method for the Study of Transamination Reactions

Sodium 1:2-naphthoquinone-4-sulfonate as a reagent for identification of amino acids and peptides and for quantitative estimation of proline and hydroxyproline separated on paper chromatograms

K. V. Giri

Papers

A Technique for the Identification of Amino-Acids separated by Circular Paper Chromatography

The isolation of allohydroxy-L-proline from sandal (Santalum album L.).

Sugar in pulses.

A Simple Paper Chromatographic Method for the Study of Transamination Reactions

Sodium 1:2-naphthoquinone-4-sulfonate as a reagent for identification of amino acids and peptides and for quantitative estimation of proline and hydroxyproline separated on paper chromatograms