This textbook presents a concise comparison of catalytic and biocatalytic systems outlining their catalytic properties and peculiarities. Moreover, it presents a brief introduction to the science of catalysis and attempts to unify different catalytic systems into a single, conceptually coherent structure. In fact, molecular dynamics and complexity may occur in both catalysts and biocatalysts, with many similarities in both their structural configuration and operational mechanisms. Moreover, the interactions between the different components of the catalytic system that are important in defining the overall activity, including the nature of active sites are discussed. Each chapter includes end of chapter questions supported by an online instructor solution manual. This textbook will be useful for undergraduate and graduate chemistry and biochemistry students.
This textbook presents a concise comparison of catalytic and biocatalytic systems outlining their catalytic properties and peculiarities. Moreover, it presents a brief introduction to the science of catalysis and attempts to unify different catalytic systems into a single, conceptually coherent structure. In fact, molecular dynamics and complexity may occur in both catalysts and biocatalysts, with many similarities in both their structural configuration and operational mechanisms. Moreover, the interactions between the different components of the catalytic system that are important in defining the overall activity, including the nature of active sites are discussed. Each chapter includes end of chapter questions supported by an online instructor solution manual. This textbook will be useful for undergraduate and graduate chemistry and biochemistry students.
Biocatalysis in Asymmetric Synthesis, a new volume in the Foundations and Frontiers of Enzymology series, offers an applied discussion of synthesizing biological catalysts using asymmetric synthesis, for applications across research and industry. Here, global experts in the field analyze a wide variety of biocatalysts and their physical states, process conditions for their asymmetric synthesis, solvents required during synthesis, and even downstream procedures for the recovery of final products. The book adopts an interdisciplinary approach, merging fundamental biology and its synthetic applications across industries, with a wide range of practical examples, from directed evolution to biotransformation and production of novel enzymes and non-conventional catalysts. Throughout the book, the impact and application of biocatalysis in sustainable processing is considered in-depth. This book will also help non-experts in biocatalysis to apply this knowledge in their own research, providing a thorough overview of the ways asymmetric biocatalytic approaches may be adapted for different disciplines and downstream products. - Explores biocatalysts as exquisite catalysts for fine chiral compound synthesis in different reaction media - Features both foundational overviews and applied, practical examples across research and industry - Includes chapter contributions from international leaders in the field
This Issue contains one communication, six articles, and two reviews. The communication from Paola Vitale et al. represents a work where whole cells were used as biocatalysts for the reduction of optically active chloroalkyl arylketones followed by a chemical cyclization to give the desired heterocycles. Among the various whole cells screened (baker’s yeast, Kluyveromyces marxianus CBS 6556, Saccharomyces cerevisiae CBS 7336, Lactobacillus reuteri DSM 20016), baker’s yeast provided the best yields and the highest enantiomeric ratios (95:5) in the bioreduction of the above ketones. In this respect, valuable chiral non-racemic functionalized oxygen-containing heterocycles (e.g., (S)-styrene oxide, (S)-2-phenyloxetane, (S)-2-phenyltetrahydrofuran), amenable to be further elaborated on, can be smoothly and successfully generated from their prochiral precursors. Studies about pure biocatalysts with mechanistical studies, application in different reactions, and new immobilization methods for improving their stability were reported in five different articles. The article by Su-Yan Wang et al. describes the cloning, expression, purification, and characterization of an N-acetylglucosamine 2-epimerase from Pedobacter heparinus (PhGn2E). For this, several N-acylated glucosamine derivatives were chemically synthesized and used to test the substrate specificity of the enzyme. The mechanism of the enzyme was studied by hydrogen/deuterium NMR. The study at the anomeric hydroxyl group and C-2 position of the substrate in the reaction mixture confirmed the epimerization reaction via ring-opening/enolate formation. Site-directed mutagenesis was also used to confirm the proposed mechanism of this interesting enzyme. The article by Forest H. Andrews et al. studies two enzymes, benzoylformate decarboxylase (BFDC) and pyruvate decarboxylase (PDC), which catalyze the non-oxidative decarboxylation of 2-keto acids with different specificity. BFDC from Pseudomonas putida exhibited very limited activity with pyruvate, whereas the PDCs from S. cerevisiae or from Zymomonas mobilis showed virtually no activity with benzoylformate (phenylglyoxylate). After studies using saturation mutagenesis, the BFDC T377L/A460Y variant was obtained, with 10,000-fold increase in pyruvate/benzoylformate. The change was attributed to an improvement in the Km value for pyruvate and a decrease in the kcat value for benzoylformate. The characterization of the new catalyst was performed, providing context for the observed changes in the specificity. The article by Xin Wang et al. compares two types of biocatalysts to produce D-lysine L-lysine in a cascade process catalyzed by two enzymes: racemase from microorganisms that racemize L-lysine to give D,L-lysine and decarboxylase that can be in cells, permeabilized cells, and the isolated enzyme. The comparison between the different forms demonstrated that the isolated enzyme showed the higher decarboxylase activity. Under optimal conditions, 750.7 mmol/L D-lysine was finally obtained from 1710 mmol/L L-lysine after 1 h of racemization reaction and 0.5 h of decarboxylation reaction. D-lysine yield could reach 48.8% with enantiomeric excess (ee) of 99%. In the article by Rivero and Palomo, lipase from Candida rugosa (CRL) was highly stabilized at alkaline pH in the presence of PEG, which permitted its immobilization for the first time by multipoint covalent attachment on different aldehyde-activated matrices. Different covalent immobilized preparation of the enzyme was successfully obtained. The thermal and solvent stability was highly increased by this treatment, and the novel catalysts showed high regioselectivity in the deprotection of per-O-acetylated nucleosides. The article by Robson Carlos Alnoch et al. describes the protocol and use of a new generation of tailor-made bifunctional supports activated with alkyl groups that allow the immobilization of proteins through the most hydrophobic region of the protein surface and aldehyde groups that allows the covalent immobilization of the previously adsorbed proteins. These supports were especially used in the case of lipase immobilization. The immobilization of a new metagenomic lipase (LipC12) yielded a biocatalyst 3.5-fold more active and 5000-fold more stable than the soluble enzyme. The PEGylated immobilized lipase showed high regioselectivity, producing high yields of the C-3 monodeacetylated product at pH 5.0 and 4 °C. Hybrid catalysts composed of an enzyme and metallic complex are also treated in this Special Issue. The article by Christian Herrero et al. describes the development of the Mn(TpCPP)-Xln10A artificial metalloenzyme, obtained by non-covalent insertion of Mn(III)-meso-tetrakis(p-carboxyphenyl)porphyrin [Mn(TpCPP), 1-Mn] into xylanase 10A from Streptomyces lividans (Xln10A). The complex was found able to catalyze the selective photo-induced oxidation of organic substrates in the presence of [RuII(bpy)3]2+ as a photosensitizer and [CoIII(NH3)5Cl]2+ as a sacrificial electron acceptor, using water as oxygen atom source. The two published reviews describe different subjects with interest in the fields of biocatalysis and mix metallic-biocatalysis, respectively. The review by Anika Scholtissek et al. describes the state-of-the-art regarding ene-reductases from the old yellow enzyme family (OYEs) to catalyze the asymmetric hydrogenation of activated alkenes to produce chiral products with industrial interest. The dependence of OYEs on pyridine nucleotide coenzyme can be avoided by using nicotinamide coenzyme mimetics. In the review, three main classes of OYEs are described and characterized. The review by Yajie Wang and Huimin Zhao highlights some of the recent examples in the past three years that combine transition metal catalysis with enzymatic catalysis. With recent advances in protein engineering, catalyst synthesis, artificial metalloenzymes, and supramolecular assembly, there is great potential to develop more sophisticated tandem chemoenzymatic processes for the synthesis of structurally complex chemicals. In conclusion, these nine publications give an overview of the possibilities of different catalysts, both traditional biocatalysts and hybrids with metals or organometallic complexes to be used in different processes—particularly in synthetic reactions—under very mild reaction conditions.
In this book, an ensemble of examples is provided to illustrate the diversity of approaches and applications to which the multi-enzyme catalysis is currently applied. Enzymes act in living beings as extremely complex, network mixtures that are supportive of all the biochemical transformations on which the life is based. In the biotechnological context, many of the enzymatic processes performed in vitro at both small and industrial scales lie on the enzymatic transformation of a single molecular species for the generation of a product and as catalyzed by a single enzyme. However, the number of technological applications for which cell-free enzyme mixtures are required is increasing and the science of how to combine individual reactions in complex processes is under speedy development. Obviously, any of the current in-progress multi-enzyme processes is fully mimicking the complexity of a living cell or cell community. However, the refined combination of selected enzymes and substrates is offering a new technological approach that is supporting the development of new or improved products in many fields such as food, leather and pharmaceutical industries. This book is unique and presents selective examples of each of these processes have been incorporated in this book by experts in their respective areas.
This introductory textbook covers all aspects of catalysis. It also bridges computational methods, industrial applications and green chemistry, with over 600 references. The book is aimed at chemistry and chemical engineering students, and is suitable for both senior undergraduate- and graduate-level courses, with many examples and hands-on exercises. The author, a renowned researcher in catalysis, is well known for his clear teaching and writing style (he was voted "lecturer of the year" by the chemistry students). Following an introduction to green chemistry and the basics of catalysis, the book covers the principles and applications of homogeneous catalysis, heterogeneous catalysis and biocatalysis. Each chapter includes up-to-date industrial examples, that demonstrate how catalysis helps our society reach the goals of sustainable development. Since its publication in 2008, Catalysis: Concepts and Green Applications has become the most popular textbook in catalysis. This second edition is updated with the latest developments in catalysis research in academia and industry. It also contains 50 additional exercises, based on the suggestions of students and teachers of chemistry and chemical engineering from all over the world. The book is also available in the Chinese language (https://detail.tmall.com/item.htm?spm=a212k0.12153887.0.0.4e60687dUTEDKm&id=619581126247). Additional teaching material (original figures as PowerPoint lecture slides) is freely available in the Supplementary Material.
Highlighting the key aspects and latest advances in the rapidly developing field of molecular catalysis, this book covers new strategies to investigate reaction mechanisms, the enhancement of the catalysts' selectivity and efficiency, as well as the rational design of well-defined molecular catalysts. The interdisciplinary author team with an excellent reputation within the community discusses experimental and theoretical studies, along with examples of improved catalysts, and their application in organic synthesis, biocatalysis, and supported organometallic catalysis. As a result, readers will gain a deeper understanding of the catalytic transformations, allowing them to adapt the knowledge to their own investigations. With its ideal combination of fundamental and applied research, this is an essential reference for researchers and graduate students both in academic institutions and in the chemical industry. With a foreword by Nobel laureate Roald Hoffmann.
