The biosynthetic pathway of vitamin C in higher plants

1998 ◽  
Vol 1 (4) ◽  
pp. 278 ◽  
Keyword(s):  
Vitamin C ◽  
Biosynthetic Pathway ◽  
Higher Plants

The biosynthetic pathway of vitamin C in higher plants

Nature ◽  
10.1038/30728 ◽  
1998 ◽  
Vol 393 (6683) ◽  
pp. 365-369 ◽  
Author(s):  
Glen L. Wheeler ◽  
Mark A. Jones ◽  
Nicholas Smirnoff
Keyword(s):  
Vitamin C ◽  
Biosynthetic Pathway ◽  
Higher Plants

scholarly journals Evolution of alternative biosynthetic pathways for vitamin C following plastid acquisition in photosynthetic eukaryotes

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Glen Wheeler ◽  
Takahiro Ishikawa ◽  
Varissa Pornsaksit ◽  
Nicholas Smirnoff
Keyword(s):  
Vitamin C ◽  
Biosynthetic Pathway ◽  
Critical Role ◽  
Biosynthetic Pathways ◽  
Oxygen Species ◽  
Photosynthetic Eukaryote ◽  
Alternative Pathways ◽  
Photosynthetic Eukaryotes ◽  
Gulonolactone Oxidase ◽  
Eukaryote Evolution

Ascorbic acid (vitamin C) is an enzyme co-factor in eukaryotes that also plays a critical role in protecting photosynthetic eukaryotes against damaging reactive oxygen species derived from the chloroplast. Many animal lineages, including primates, have become ascorbate auxotrophs due to the loss of the terminal enzyme in their biosynthetic pathway, l-gulonolactone oxidase (GULO). The alternative pathways found in land plants and Euglena use a different terminal enzyme, l-galactonolactone dehydrogenase (GLDH). The evolutionary processes leading to these differing pathways and their contribution to the cellular roles of ascorbate remain unclear. Here we present molecular and biochemical evidence demonstrating that GULO was functionally replaced with GLDH in photosynthetic eukaryote lineages following plastid acquisition. GULO has therefore been lost repeatedly throughout eukaryote evolution. The formation of the alternative biosynthetic pathways in photosynthetic eukaryotes uncoupled ascorbate synthesis from hydrogen peroxide production and likely contributed to the rise of ascorbate as a major photoprotective antioxidant.

scholarly journals L-Tartaric acid synthesis from vitamin C in higher plants

2006 ◽  
Vol 103 (14) ◽  
pp. 5608-5613 ◽  
Author(s):  
S. DeBolt ◽  
D. R. Cook ◽  
C. M. Ford
Keyword(s):  
Vitamin C ◽  
Tartaric Acid ◽  
Higher Plants ◽  
Acid Synthesis

scholarly journals Dissection of the general two-step di-C-glycosylation pathway for the biosynthesis of (iso)schaftosides in higher plants

2020 ◽  
Vol 117 (48) ◽  
pp. 30816-30823
Author(s):  
Zi-Long Wang ◽  
Hao-Meng Gao ◽  
Shuang Wang ◽  
Meng Zhang ◽  
Kuan Chen ◽  
...  
Keyword(s):  
Defense Mechanisms ◽  
Biosynthetic Pathway ◽  
Higher Plants ◽  
Cereal Crops ◽  
High Homology ◽  
Efficient Synthesis ◽  
Bioactive Natural Products ◽  
Homologous Genes ◽  
Glycosylation Pathway

Schaftoside and isoschaftoside are bioactive natural products widely distributed in higher plants including cereal crops and medicinal herbs. Their biosynthesis may be related with plant defense. However, little is known on the glycosylation biosynthetic pathway of these flavonoid di-C-glycosides with different sugar residues. Herein, we report that the biosynthesis of (iso)schaftosides is sequentially catalyzed by twoC-glycosyltransferases (CGTs), i.e., CGTa forC-glucosylation of the 2-hydroxyflavanone aglycone and CGTb forC-arabinosylation of the mono-C-glucoside. The two enzymes of the same plant exhibit high homology but remarkably different sugar acceptor and donor selectivities. A total of 14 CGTa and CGTb enzymes were cloned and characterized from seven dicot and monocot plants, includingScutellaria baicalensis,Glycyrrhiza uralensis,Oryza sativassp.japonica, andZea mays, and the in vivo functions for three enzymes were verified by RNA interference and overexpression. Through transcriptome analysis, we found homologous genes in 119 other plants, indicating this pathway is general for the biosynthesis of (iso)schaftosides. Furthermore, we resolved the crystal structures of five CGTs and realized the functional switch of SbCGTb to SbCGTa by structural analysis and mutagenesis of key amino acids. The CGT enzymes discovered in this paper allow efficient synthesis of (iso)schaftosides, and the general glycosylation pathway presents a platform to study the chemical defense mechanisms of higher plants.

scholarly journals Investigation of the subcellular location of the tetrapyrrole-biosynthesis enzyme coproporphyrinogen oxidase in higher plants

1993 ◽  
Vol 292 (2) ◽  
pp. 503-508 ◽  
Author(s):  
A G Smith ◽  
O Marsh ◽  
G H Elder
Keyword(s):  
Biosynthetic Pathway ◽  
Higher Plants ◽  
Protoporphyrin Ix ◽  
Subcellular Location ◽  
Subcellular Fractionation ◽  
Radiochemical Method ◽  
Coproporphyrinogen Oxidase ◽  
Isotonic Buffer ◽  
Arum Maculatum ◽  
Cellular Organelles

The subcellular location of two enzymes in the biosynthetic pathway for protoporphyrin IX, coproporphyrinogen (coprogen) oxidase (EC 1.3.3.3) and protoporphyrinogen (protogen) oxidase (EC 1.3.3.4) has been investigated in etiolated pea (Pisum sativum) leaves and spadices of cuckoo-pint (Arum maculatum). Plant tissue homogenized in isotonic buffer was subjected to subcellular fractionation to prepare mitochondria and plastids essentially free of contamination by other cellular organelles, as determined by marker enzymes. Protogen oxidase activity measured fluorimetrically was reproducibly found in both mitochondria and etioplasts. In contrast, coprogen oxidase could be detected only in etioplasts, using either a coupled fluorimetric assay or a sensitive radiochemical method. The implications of these results for the synthesis of mitochondrial haem in plants is discussed.

scholarly journals The efficacy and safety of a 70% glycolic acid peel with vitamin C for the treatment of photoaging

2017 ◽  
Vol 2 (3) ◽  
Author(s):  
Yang Shiyao Sam ◽  
Liau MeiQi May ◽  
Heng Jun Khee ◽  
Toh Han Sim Matthias ◽  
Aw Chen Wee Derrick ◽  
...  
Keyword(s):  
Patient Satisfaction ◽  
Vitamin C ◽  
Effective Treatment ◽  
Clinical Experience ◽  
Safety Profile ◽  
Biosynthetic Pathway ◽  
Glycolic Acid ◽  
Efficacy And Safety ◽  
Photoaged Skin ◽  
Excellent Safety Profile

<p>Glycolic acid peels have been shown in many studies to improve the appearance of photoaged skin. Vitamin C is known to be a potent natural antioxidant and plays an important role in the collagen biosynthetic pathway. In this study, we report our clinical experience with 70% glycolic acid peel added with vitamin C. We found that all parameters of photoaging, in particular the composite wrinkling score, discolouration score and the global photoaged score, showed statistically significant improvement. Patient satisfaction also revealed improvement in keeping with the physician assessment. It is also associated with an excellent safety profile. In conclusion, a combination of 70% glycolic acid with vitamin C chemical peel is a well-tolerated effective treatment of photoaging in Asian skin.</p>

scholarly journals The terminal step in vitamin C biosynthesis in Trypanosoma cruzi is mediated by a FMN-dependent galactonolactone oxidase

2007 ◽  
Vol 407 (3) ◽  
pp. 419-426 ◽  
Author(s):  
Flora J. Logan ◽  
Martin C. Taylor ◽  
Shane R. Wilkinson ◽  
Harparkash Kaur ◽  
John M. Kelly
Keyword(s):  
Vitamin C ◽  
Trypanosoma Cruzi ◽  
Trypanosoma Brucei ◽  
Biosynthetic Pathway ◽  
Site Directed Mutagenesis ◽  
Binding Motif ◽  
Cofactor Binding ◽  
Tryptophan Residues ◽  
Gulonolactone Oxidase ◽  
Flavin Binding

Humans lack the ability to synthesize vitamin C (ascorbate) due to the absence of gulonolactone oxidase, the last enzyme in the biosynthetic pathway in most other mammals. The corresponding oxidoreductase in trypanosomes therefore represents a target that may be therapeutically exploitable. This is reinforced by our observation that Trypanosoma cruzi, the causative agent of Chagas' disease, lacks the capacity to scavenge ascorbate from its environment and is therefore dependent on biosynthesis to maintain intracellular levels of this vitamin. Here, we show that T. cruzi galactonolactone oxidase (TcGAL) can utilize both L-galactono-γ-lactone and D-arabinono-γ-lactone as substrates for synthesis of vitamin C, in reactions that obey Michaelis–Menten kinetics. It is >20-fold more active than the analogous enzyme from the African trypanosome Trypanosoma brucei. FMN is an essential cofactor for enzyme activity and binds to TcGAL non-covalently. In other flavoproteins, a histidine residue located within the N-terminal flavin-binding motif has been shown to be crucial for cofactor binding. Using site-directed mutagenesis, we show that the corresponding residue in TcGAL (Lys-55) is not essential for this interaction. In contrast, we find that histidine and tryptophan residues (His-447 and Trp-448), localized within a C-terminal motif (HWXK) that is a feature of ascorbate-synthesizing enzymes, are necessary for the FMN association. The conserved lysine residue within this motif (Lys-450) is not required for cofactor binding, but its replacement by glycine renders the protein completely inactive.

Sign in / Sign up

Export Citation Format

Share Document