Evolution of fluorinated enzymes: an emerging trend for biocatalyst stabilization

Nature uses remarkably limited sets of chemistries in its repertoire, especially when compared to synthetic organic chemistry. This limits both the chemical and structural diversity that can ultimately be achieved with biocatalysis, unless the powers of chemical synthesis are merged with biological systems by integrating nonnatural synthetic chemistries into the protoplasma of living cells. Of particular interest, here is the fluorous effect that has recently established the potential to generate enzymes with an increased resistance toward both high temperature and organic solvents. For these reasons, we are witnessing a rapid development of efficient methodologies for the incorporation of fluorinated amino acids in protein synthesis, using both in vivo and in vitro strategies. In this review, we highlight relevant and trendsetting results in the design and engineering of stable fluorinated proteins and peptides along with whole-cell biocatalysis as an economically attractive and convenient application with exclusive focus on industrial biocatalysis. Finally, we envision new strategies to improve current achievements and enable the field to progress far beyond the current state-of-the-art.DFG, EXC 314, Unifying Concepts in Catalysi

Peroxidase activity of dimanganese(III) complexes with the [Mn2(μ-OAc)(μ-OR)2]3+ core

Catalytic activity of three dinuclear MnIII complexes of general formula [Mn2(μ-OAc)(μ-OMe)(L)]BPh4 (H3L = 1,5-bis[(2-hydroxy-5-X-benzyl)(2-pyridylmethyl)amino] pentan-3-ol, 1: X = H, 2: X = OMe, 3: X = Br) in the oxidation of phenol, 2,6-dimethoxyphenol and wood pulp by H2O2 has been investigated. The role of pH, electronic properties of the ligand and metal coordination environment on the ability of these complexes to activate H2O2 has been examined. The three catalysts showed similar activity independently of the aromatic substituent in the ligand and were found to be 2-3 times more active at pH 9.00 than at neutral pH. Bleaching of Kraft pulp by H2O2 activated by 1 in alkaline media decreased the kappa number of the pulp by 16%, at room temperature and low catalyst concentration, without damage of cellulose fibers. It was found that the exchange of the methoxo- and acetato-bridges by an oxo-bridge reduces the catalytic activity of these compounds, probably by direct binding of phenolate to a vacant site on the metal center.Fil: Biava, Hernan Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; ArgentinaFil: Signorella, Sandra Rosanna. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; Argentin

Orthogonal Translation Meets Electron Transfer: In Vivo Labeling of Cytochrome c for Probing Local Electric Fields

Cytochrome c (cyt c), a redox protein involved in diverse fundamental biological processes, is among the most traditional model proteins for analyzing biological electron transfer and protein dynamics both in solution and at membranes. Studying the role of electric fields in energy transduction mediated by cyt c relies upon appropriate reporter groups. Up to now these had to be introduced into cyt c by in vitro chemical modification. Here, we have overcome this restriction by incorporating the noncanonical amino acid p-cyanophenylalanine (pCNF) into cyt c in vivo. UV and CD spectroscopy indicate preservation of the overall protein fold, stability, and heme coordination, whereas a small shift of the redox potential was observed by cyclic voltammetry. The C≡N stretching mode of the incorporated pCNF detected in the IR spectra reveals a surprising difference, which is related to the oxidation state of the heme iron, thus indicating high sensitivity to changes in the electrostatics of cyt c.Fil: Völler, Jan. Technishe Universitat Berlin; AlemaniaFil: Biava, Hernan Daniel. Technishe Universitat Berlin; Alemania. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Química Rosario; ArgentinaFil: Koksch, Beate. Freie Universitä t Berlin; AlemaniaFil: Hildebrandt, Peter. Technishe Universitat Berlin; AlemaniaFil: Budisa, Nediljko. Technishe Universitat Berlin; Alemani

Cellulose recycling as a source of raw chirality

Modern organic chemistry requires easily obtainable chiral building blocks that show high chemical versatility for their application in the synthesis of enantiopure compounds. Biomass has been demonstrated to be a widely available raw material that represents the only abundant source of renewable organic carbon. Through the pyrolitic conversion of cellulose or cellulose-containing materials it is possible to produce levoglucosenone, a highly functionalized chiral structure. This compound has been innovatively used as a template for the synthesis of key intermediates of biologically active products and for the preparation of chiral auxiliaries, catalysts, and organocatalysts for their application in asymmetric synthesis.Fil: Biava, Hernan Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Química Rosario; ArgentinaFil: Spanevello, Rolando Angel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Química Rosario; ArgentinaFil: Suarez, Alejandra Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Química Rosario; ArgentinaFil: Mata, Ernesto Gabino. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Química Rosario; ArgentinaFil: Mangione, Maria Ines. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Química Rosario; ArgentinaFil: Sarotti, Ariel Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Química Rosario; ArgentinaFil: Corne, Valeria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Química Rosario; ArgentinaFil: Botta, María Celeste. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Química Rosario; ArgentinaFil: Giordano, Enrique David Victor. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Química Rosario; ArgentinaFil: Giri, German Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Química Rosario; ArgentinaFil: Llompart, David Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Química Rosario; Argentin

Development of polymer-supported chiral aminoalcohols derived from biomass and their application to asymmetric alkylation

A synthetic strategy has been developed for the preparation of immobilized 1,2-aminoalcohols starting from easily available and renewable chiral building blocks. They were tested as chiral ligands for the asymmetric diethylzinc addition to carbonyl compounds. Enantioselectivities were comparable to those observed for non-immobilized analogs. These results provide strong evidence for the flexibility of our approach to generate highly valuable supported chiral ligands derived from cellulose-rich materials.Fil: Botta, María Celeste. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; ArgentinaFil: Biava, Hernan Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; ArgentinaFil: Spanevello, Rolando Angel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; ArgentinaFil: Mata, Ernesto Gabino. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; ArgentinaFil: Suarez, Alejandra Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; Argentin

Discovery and Investigation of Natural Editing Function against Artificial Amino Acids in Protein Translation

[Image: see text] Fluorine being not substantially present in the chemistry of living beings is an attractive element in tailoring novel chemical, biophysical, and pharmacokinetic properties of peptides and proteins. The hallmark of ribosome-mediated artificial amino acid incorporation into peptides and proteins is a broad substrate tolerance, which is assumed to rely on the absence of evolutionary pressure for efficient editing of artificial amino acids. We used the well-characterized editing proficient isoleucyl-tRNA synthetase (IleRS) from Escherichia coli to investigate the crosstalk of aminoacylation and editing activities against fluorinated amino acids. We show that translation of trifluoroethylglycine (TfeGly) into proteins is prevented by hydrolysis of TfeGly-tRNA(Ile) in the IleRS post-transfer editing domain. The remarkable observation is that dissociation of TfeGly-tRNA(Ile) from IleRS is significantly slowed down. This finding is in sharp contrast to natural editing reactions by tRNA synthetases wherein fast editing rates for the noncognate substrates are essential to outcompete fast aa-tRNA dissociation rates. Using a post-transfer editing deficient mutant of IleRS (IleRSAla10), we were able to achieve ribosomal incorporation of TfeGly in vivo. Our work expands the knowledge of ribosome-mediated artificial amino acid translation with detailed analysis of natural editing function against an artificial amino acid providing an impulse for further systematic investigations and engineering of the translation and editing of unusual amino acids