Conversion of Biosynthetic Precursors of RNA to Those of ..
The human IGF-2R-coding gene is situated onchromosome 6q25–q27 ().Extracellular domain consists of 15 segments, each containing from134 to 191 aa and a small region homologous to the collagen-bindingdomain of fibronectin (). Mousegene of 93 kb in length, includes 48 exons and codes for a proteinwith 2482 aa (). The receptoritself is identical with cation-independent IGF-2/MPR (,).IGF-2R binds IGF-2 ∼500 higher than IGF-1 (). IGF-2R is a multifunctional proteinand plays a principal role in sorting and transport of lysosomalenzymes from sites of their synthesis to appropriate cellularcompartments and in control of proteins containingmannose-6-phosphate. The receptor is of potential significance formaturation and clearance of growth factors and it mediatesIGF-2-activated signal transduction through a G-protein-coupledmechanism (,). In studies on mice IGF-2R wasdemonstrated to be paternally imprinted, and to be crucial forregulating normal fetal growth, circulating IGF-2, and heartdevelopment ().
Some of the precursors necessary for the synthesis …
IGF-1 may play a role both in persistence ofchronic hepatic inflammation through control of signaling pathwayslinked to proinflammatory cytokines and receptors for endothelialadhesion molecules (e.g. ICAM-1) (), and in induction of acuteinflammatory reaction, triggered by tumour cells during earlystages of liver metastasis (,,). In recent years increasedattention is devoted also to complex interactions between HCVproteins and IGF axis. HCV core protein was shown to increaseendogenous expression of IGF-2 in HepG2 cell line, regulatingpositively its transcription, and it may promote cell divisions().
Pyrimidines are synthesized first from aspartate and carbamoyl-phosphate in the cytoplasm to the common precursor ring structure (C00295), onto which a phosphorylated ribosyl unit is covalently linked.
Nucleotide Metabolism: Nucleic Acid Synthesis
AB - Because of the expected greater rate of coupling as compared to naphthylamine, 3-methoxy-1-naphthylamine and 4-methoxy-2-naphthylamiue have been synthesized for use in the preparation of chromogenic substrates for the histochemical demonstration of amidases and peptidases. The chloroacetamides, trifluoroacetamides and L-leucyl-4-methoxy-2-naphthyl amide also were prepared. The last derivative is a superior reagent for the histochemical demonstration of leucine amino peptidase.
Amino acid synthesis - Wikipedia
Carbon nanomaterials have huge potential in the field of energy and environmental applications. However, a wide range of greener and environment friendly synthesis methods utilizing natural, renewable, cheaper waste materials has to be developed. This will lead to the reduction of green house gases, exploitation of toxic materials and helps in the development of sustainable technologies. In this review, the details progress made in the last ten years concerning the synthesis of new one dimensional (carbon nanotubes CNT, carbon nanofiber) and two dimensional (graphene) carbon based materials using natural precursors and waste materials is summarized. The aim of this review paper is to provide a comprehensive scientific progress of synthesis of graphene and carbon nanotubes using natural precursor and waste materials for the future perspective. This paper also concludes with a brief discussion on the impact of natural precursor for the graphene and CNTs for environment, its toxicological effects and its future prospects in this rapidly emerging field. Natural precursors and waste carbon containing products are emerging as a new class of materials that have efficiency to produce graphene and CNTs. The various synthesis processes of graphene, CNTs and carbon dots has been reported using several natural hydrocarbon precursors (turpentine oil, eucalyptus oil, palm oil, neem oil, sunflower oil, castor oil, biodiesel, tea-tree extract, honey, milk, sugar, butter, egg etc.). Also, some research groups have used foods wastes (cookie and chocolate), vegetation wastes (woods, leaf, grass, fruit wastes), animal/bird/insect wastes (bone and cow dung, dog feces, chicken feather) and agro waste (sugarcane bagasse) for the synthesis of graphene and CNTs. Research on natural hydrocarbon precursors and wastage materials has increased in recent years as they promise to produce better and high quality of graphene and CNTs in large quantities. The fascinating aspect of this research area is that it guides the use of natural hydrocarbons to explore the possibilities of improving graphene stability and robustness suitable for different type of applications.
Disulfide synthesis by S-S coupling - Organic chemistry
Soon after the origin of RNA-based life, depletion of prebiotically synthesised ribonucleotides would have driven the evolution of a biosynthetic pathway to these key building blocks. Ribozyme-catalysed nucleosidation—the key biosynthetic step—requires that ribose and the nucleobases are produced by abiotic chemistry and are relatively stable to the conditions of their synthesis. The most plausible prebiotic synthesis of sugars involves photoreduction of cyanohydrins by hydrogen sulphide in the presence of copper(I) cyanide, and we therefore subjected ribose to these conditions whereupon it was partially converted to 2-deoxyribose. Furthermore, a derivative of uracil is reduced under similar conditions to thymine. Thus, DNA biosynthetic precursors can be formed abiotically from those of RNA allowing for an early evolutionary transition to life based on RNA and DNA.