118758-45-5Relevant academic research and scientific papers
Remote C-H Hydroxylation by an α-Ketoglutarate-Dependent Dioxygenase Enables Efficient Chemoenzymatic Synthesis of Manzacidin C and Proline Analogs
Zwick, Christian R.,Renata, Hans
, p. 1165 - 1169 (2018)
Selective C-H functionalization at distal positions remains a highly challenging problem in organic synthesis. Though Nature has evolved a myriad of enzymes capable of such feat, their synthetic utility has largely been overlooked. Here, we functionally characterize an α-ketoglutarate-dependent dioxygenase (Fe/αKG) that selectively hydroxylates the ? position of various aliphatic amino acids. Kinetic analysis and substrate profiling of the enzyme show superior catalytic efficiency and substrate promiscuity relative to other Fe/αKGs that catalyze similar reactions. We demonstrate the practical utility of this transformation in the concise syntheses of a rare alkaloid, manzacidin C, and densely substituted amino acid derivatives with remarkable step efficiency. This work provides a blueprint for future applications of Fe/αKG hydroxylation in complex molecule synthesis and the development of powerful synthetic paradigms centered on enzymatic C-H functionalization logic.
3-Hydroxylysine, a potential marker for studying radical-induced protein oxidation
Morin, Eedicte,Bubb, William A.,Davies, Michael J.,Dean, Roger T.,Fu, Shanlin
, p. 1265 - 1273 (2007/10/03)
γ-Irradiation of several amino acids (Val, Leu, Ile, Lys, Pro, and Glu) in the presence of O2 generates hydroperoxides. We have previously isolated and characterized valine and leucine hydroperoxides, and hydroxides, and have detected these products in both isolated systems [e.g., bovine serum albumin (BSA) and human low-density lipoprotein (LDL)] and diseased human tissues (atherosclerotic plaques and lens cataractous proteins). This work was aimed at investigating oxidized lysine as a sensitive marker for protein oxidation, as such residues are present on protein surfaces, and are therefore likely to be particularly susceptible to oxidation by radicals in bulk solution. HO°attack on lysine in the presence of oxygen, followed by NaBH4 reduction, is shown to give rise to (2S)-3-hydroxylysine [(2S)-2,6-diamino-3- hydroxyhexanoic acid], (2S)-4-hydroxylysine [(2S)-2,6-diamino-4- hydroxyhexanoic acid], (2S,5R)5-hydroxylysine [(2S,5R)-2,6-diamino-5- hydroxyhexanoic acid], and (2S,5S)-5-hydroxylysine [(2S,5S)-2,6-diamino-5- hydroxyhexanoic acid]. 5-Hydroxylysines are natural products formed by lysyl oxidase and are therefore not good markers of radical-mediated oxidation. The other hydroxylysines are however useful markers, with HPLC analysis of 9- fluorenylmethyl chloroformate (FMOC) derivatives providing a sensitive and accurate method for quantitative measurement. Hydroxylysines have been detected in the hydrolysates of peptides (Gly-Lys-Gly and Lys-Val-Ile-Leu- Phe) and proteins (BSA and histone H1) exposed to HO°/O2, and subsequently treated with NaBH4. Quantification of the hydroxylysines yields, and comparison with hydroxyvalines and hydroxyleucines, supports the hypothesis that surface residues give higher yields of oxidized products than the hydrophobic leucines and valines, at least with globular proteins such as BSA. Hydroxylysines, and particularly 3-hydroxylysine, may therefore be sensitive and useful markers of radical-mediated protein oxidation in biological systems.
