4214-13-5Relevant articles and documents
Significant improvement of oxidase activity through the genetic incorporation of a redox-active unnatural amino acid
Yu, Yang,Zhou, Qing,Wang, Li,Liu, Xiaohong,Zhang, Wei,Hu, Meirong,Dong, Jianshu,Li, Jiasong,Lv, Xiaoxuan,Ouyang, Hanlin,Li, Han,Gao, Feng,Gong, Weimin,Lu, Yi,Wang, Jiangyun
, p. 3881 - 3885 (2015)
While nature employs various covalent and non-covalent strategies to modulate tyrosine (Y) redox potential and pKa in order to optimize enzyme activities, such approaches have not been systematically applied for the design of functional metalloproteins. Through the genetic incorporation of 3-methoxytyrosine (OMeY) into myoglobin, we replicated important features of cytochrome c oxidase (CcO) in this small soluble protein, which exhibits selective O2 reduction activity while generating a small amount of reactive oxygen species (ROS). These results demonstrate that the electron donating ability of a tyrosine residue in the active site is important for CcO function. Moreover, we elucidated the structural basis for the genetic incorporation of OMeY into proteins by solving the X-ray structure of OMeY specific aminoacyl-tRNA synthetase complexed with OMeY.
Synthesis of a Photo-Caged DOPA Derivative by Selective Alkylation of 3,4-Dihydroxybenzaldehyde
Schneider, Tobias,Kubyshkin, Vladimir,Budisa, Nediljko
, p. 2053 - 2063 (2018/05/31)
Natural and synthetic polymers containing the catechol moiety of noncoded amino acid 3,4-dihydroxyphenylalanine (DOPA) are capable of metal-coordination and adhesion under wet conditions. Masking the catechol subunit with a photo-cleavable group would provide an opportunity to design tunable adhesion properties that are especially important for biomaterial and biomedicine applications. Herein, we report the regioselective synthesis of a photo-caged DOPA bearing an ortho-nitrobenzyl (oNB) group that is capable of undergoing cleavage upon irradiation with UV light. We developed a selective synthetic route towards a 3-O-oNB alkylated DOPA regioisomer that can be readily incorporated into proteins by using a previously developed bio-expression platform. The synthesis is based on a regioselectivity switch in 3,4-dihydrozybenzaldehyde alkylation upon application of different equivalents of deprotonating base. The enantiomerically pure 3-O-oNB-DOPA was prepared on a gram scale and proved to be generally compatible with the solid-phase peptide synthesis conditions. We also demonstrate the general applicability of the developed synthetic strategy by providing the synthesis of 3-O-methyl-DOPA.
Cutting long syntheses short: Access to non-natural tyrosine derivatives employing an engineered tyrosine phenol lyase
Seisser, Birgit,Zinkl, Rene,Gruber, Karl,Kaufmann, Franz,Hafner, Andreas,Kroutil, Wolfgang
experimental part, p. 731 - 736 (2010/06/21)
The chemical synthesis of 3-substituted tyrosine derivatives requires a minimum of four steps to access optically enriched material starting from commercial precursors. Attempting to short-cut the cumbersome chemical synthesis of 3-substituted tyrosine derivatives, a single step biocatalytic approach was identified employing the tyrosine phenol lyase from Citrobacter freundii. The enzyme catalyses the hydrolysis of tyrosine to phenol, pyruvate and ammonium as well as the reverse reaction, thus the formation of tyrosine from phenol, pyruvate and ammonium. Since the wild-type enzyme possessed a very narrow substrate spectrum, structure-guided, site-directed mutagenesis was required to change the substrate specificity of this C-C bond forming enzyme. The best variant M379V transformed, for example, o-cresol, o-methoxyphenol and o-chlorophenol efficiently to the corresponding tyrosine derivatives without any detectable side-product. In contrast, all three phenol compounds were non-substrates for the wild-type enzyme. Employing the mutant, various Ltyrosine derivatives (3-Me, 3-OMe, 3-F, 3-Cl) were obtained with complete conversion and excellent enantiomeric excess (>97%) in just a single 'green' step starting from pyruvate and commercially available phenol derivatives.
