Nature, Function, and Biosynthesis of Surfactant Lipids
Jacques R. Bourbon in Pulmonary Surfactant: Biochemical, Functional, Regulatory, and Clinical Concepts, 2019
Indeed, pathways of PC biosynthesis do not differ fundamentally between surfactant PC and PC of other cell compartments. One must keep in mind that lung cells other than type II cells also synthesize PC and that only 30% of DPPC produced by the lung is destined to surfactant.111 The specificity of surfactant does not reside in the presence of a unique phospholipid molecule, but rather in the unusual proportion of DPPC among the various molecular species of PC. Therefore, the specificity of type II cell-phospholipid biosynthetic activity is more in the details of the mechanisms which lead to the preferential incorporation of palmitate into PC than in the general aspects of PC biosynthesis that it shares with other cells. After a brief description of the successive steps of the biosynthetic pathway (for details, see, for instance, papers reviewed in References 1, 112, and 113), the mechanisms which account for the preferential synthesis of saturated species of PC will be more thoroughly considered.
Impact of Integrated Omics Technologies for Identification of Key Genes and Enhanced Artemisinin Production in Artemisia annua L.
Tariq Aftab, M. Naeem, M. Masroor, A. Khan in Artemisia annua, 2017
As for other terpenes, AN biosynthesis involves two pathways: the cytosolic “mevalonate (MVA) pathway” and the plastidic “non-mevalonate/MEP pathway.” These two pathways are involved in the formation of two isoprenoid precursors: isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP). Two stages of AN biosynthesis have now been completely elucidated: the formation of farnesyl diphosphate (FPP) and the cyclization of FPP to form amorpha-4,11-diene, which ultimately leads to the synthesis of AN and its various other derivatives. All the biosynthetic pathway genes and their sequences and functions have already been reported in A. annua (Bouwmeester et al. 1999). The transcriptomes of leaves and glandular trichomes of A. annua have also been well characterized, as, later, has the site of AN biosynthesis (Arsenault et al. 2010; Olofsson et al. 2011). The transcriptome data are very helpful in manipulating the biosynthetic pathways to channelize the carbon flux for enhanced AN synthesis by either upregulation of the desired pathway or downregulation of competing pathways through overexpression and/or suppression of their respective pathway genes.
Potential Significance of Proteases
Hafiz Ansar Rasul Suleria, Megh R. Goyal, Masood Sadiq Butt in Phytochemicals from Medicinal Plants, 2019
Enzymes are protein in nature that accelerate the biochemical reactions as per life processes, which are essential, including respiration, digestion, maintenance of tissues, and metabolism. They have an ability to remove or add atoms to a molecule, join together smaller molecules, and split a large molecule into smaller ones. In other words, they are highly specific biological catalysts. Enzymes have the ability to work under more or less mild conditions and they become superlative or ideal catalyst to be used in food technology.15 Enzymes catalyze many biochemical reactions needed to sustain the life and present in all living organisms. They are metabolized and broken down after intake similar to other proteins of diet. Enzymes are believed to be naturally safe and considered as nontoxic.17
Advances in biocatalytic and chemoenzymatic synthesis of nucleoside analogues
Published in Expert Opinion on Drug Discovery, 2022
Sebastian C. Cosgrove, Gavin J. Miller
A pioneering example of a fully engineered biosynthetic pathway was reported by Birmingham et al. [30]. The authors described an engineering campaign of a suite of biocatalysts, to deliver a five-enzyme cascade toward the nucleoside analogue didanosine 5, which is used as a combination antiretroviral treatment for HIV/AIDS [31]. A bioretrosynthetic approach was used to design the pathway to 5. Inspired by a nucleoside salvage pathway (Scheme 3A), the group focussed on the pathway for inosine 3, closely related to their target. By running this degradative pathway in reverse, it was theorized that the enzymes could be engineered for activity toward non-natural components and deliver a biocatalytic cascade to synthesize 5.
Molecular diagnosis of coenzyme Q10 deficiency: an update
Published in Expert Review of Molecular Diagnostics, 2018
Delia Yubero, Raquel Montero, Carlos Santos-Ocaña, Leonardo Salviati, Placido Navas, Rafael Artuch
It is important to note that all cells have the capacity to synthesize CoQ, but its availability also comes from dietary sources, which influence plasmatic levels up to 25% of the total amount [5]. However, the distribution of plasma CoQ through cells and organs seems limited. Thus, every mammalian cell produces CoQ, likely because CoQ is poorly absorbed into cells and tissues [6]. The biosynthetic pathway has not been fully elucidated. It has been recently demonstrated that a CoQ biosynthesis complex also exists in mammals [7–9], even though numerous questions about CoQ biosynthesis complex components, structure, assembly, regulation, and activity remain unanswered. Fifteen genes have been shown to be required for the condensation and metabolism of CoQ (Figure 1); hence, the metabolic pathway for CoQ biosynthesis is complex, and several conditions (both genetic defects and environmental factors), could impair a proper CoQ synthesis.
An update on gene therapy for lysosomal storage disorders
Published in Expert Opinion on Biological Therapy, 2019
Murtaza S. Nagree, Simone Scalia, William M. McKillop, Jeffrey A. Medin
While HSCs are promising targets for ex vivo gene therapy, acquiring, enriching, and transplanting these cells can be technically challenging [54]. Systemic administration is an attractive alternative to HSC-directed gene therapy, as it requires only an intravenous injection and can theoretically lead to transduction of many organ systems. However, systemic administration requires a large amount of expensive clinical-grade vector. In early studies on vector trafficking and transduction, systemically administered vector was found to predominantly transduce the liver [55,56]. The liver is an attractive transduction target as it is a major protein producing biosynthetic organ central to metabolism, and long-term gene expression has been noted in transduced hepatocytes [55,57]. In the LSD field, systemic injection of both recombinant LV and recombinant AAV has been investigated (see following).