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Biotechnological applications of proteins and enzymes
International comment does the academic side do with a 'hot idea', which must take its place in a long queue? The NBST and the IDA provide grants for R&D in process and product development, but many of those are directed to companies rather than to research groups as such. Irish based companies in the areas of enzyme
and microbial technology having R&D facilities are few and far between, so that a link-up with industry is usually difficult in these areas. One possible solution now being tested by a group of individual researchers in University College, Galway, is the formation of a limited company as a vehicle for R&D
and eventual commercialization of ideas. It remains to be seen how this will develop, and it may be the subject of a further report in this column at a later date. D. B. Johnson
Biotechnological Applications of Proteins and Enzymes
book is conveniently divided into four main parts. The first part, 'The Production of Enzymes', although not encompassed by the book's title, nevertheless does provide a useful background to the central theme. Thus, 'Selection of Bacteria as Sources of Enzymes' by Hed6n features recent advances in the automatic mapping of the enzymatic potential of microorganisms and in computer-controlled steering of continuous cultures towards optimal production. Heden also rightfully stresses the increasing importance of microorganisms as an international resource. Aunstrup's contribution 'Industrial Approach to Enzyme Production', being mostly confined to enzyme production from microorganisms, is not as broadly based as its title suggests. Consequently, much material is repeated in the next chapter, 'The Microbial Production of Enzymes' by Solomons. However, other methods of enzyme production are covered in a balanced contribution on 'Production of Enzymes and Proteins in Tissue Culture', by Pye e t al. This chapter comprehensively reviews the increasingly acknowledged potential of tissue culture for the production of many biologically important compounds, including human insulin, interferon, growth hormone and hormonal glycoproteins (FSH, LH) which otherwise are difficult to obtain in quantity. The next and major part, 'Exploitation of Soluble and Insolubilized Enzymes', opens with 'Protein Insolubilization and Affinity Chromatography' by Porath and Caldwell. Recent developments by the authors and their collaborators in the use of chemically-modified dextran and agarose as supports for the chromatography of proteins, peptides and amino acids by reversible insolubilization are extensively reviewed. Several imaginative approaches to reversible protein insolubilization are described,
including hydrophobic affinity adsorption, charge-transfer adsorption and chelation to insolubilized metal ions. 'Industrial Application of Immobilized Enzymes: Present State of the Art' by Weetall covers both large- and small-scale applications in general. Since the industrial exploitation of immobilized enzymes is proving rather sluggish, this chapter holds few surprises. Unfortunately, some terms invoked by Weetall, for example 'half-life', have objectionable definition or application. As Lilly aptly points out in the following chapter, 'A Comparison of Ceils and Enzymes as Industrial Catalysts', many immobilized enzymes lose activity by non-first order processes and so the term 'half-life' should not be applied to them. Even so, this message remains unheeded in later chapters. In a diverse and interesting contribution, ' " T o getherness" through Immobilization', Mosbach describes catalytically efficient systems of immobilized enzyme and enzyme coenzyme combinations, and the analytical utility of these systems when in combination with electrodes or thermistors. Goldstein e t al. in 'Chemically Modified Polymers Containing lsocyanide Functional Groups as Supports for Enzyme Immobilization', illustrate the scope and versatility of the Passerini and four-component condensation reactions for the production of isocyanide groups in c o m m e r c i a l polymers and for the coupling of enzymes to such groups. The elimination of diffusion effects by pressure filtration through microporous enzymatic membranes is described in the only kinetics-based paper, 'Effectiveness of Enzyme membrane Filtration Reactors' by Simon e t al. Both the final contributions to this part discuss biotransformations. Thus, important examples of multienzyme syntheses, of the antibiotics f, ramicidin S and Bacitracin A, are thoroughly discussed
Editors: Zvi Bohak and Nathan Sharon Academic Press, New Y o r k San Francisco -- London, 1977, xliv + 367 pp., £21.60, US $33.00
Whereas its title is not incorrect, 'Biotechnological Applications of Proteins and Enzymes' is sufficiently broad yet progressive to rouse the inquisitorial instincts in biological chemists, biochemists and medical biochemists. Although the book is the outcome of a conference held in Israel in 1976 to honour the sixtieth birthday of Professor Ephraim KatchalskiKatzir, former President of the State of Israel, it is a collection of useful reviews rather than a conglomerate of highly specialized original research papers. These reviews cover a diversity, but not all aspects, of current and imminent applications of proteins etc. in industry, medicine and nutrition, and circumscribe the underlying technological and economic constraints of such applications. 'Biotechnological Applications of Proteins and Enzymes' opens with a biography describing Professor Katzir's pioneering work in the development of biotechnological applications of proteins and enzymes, and on his significant contributions to the scientific, educational and political life of Israel. Thereafter, Sir Ernst Chain discusses 'The Position of Applied Research in Non-industrial Laboratories'. The topic is 'too broad to be covered in one paper' and so the arguments presented and conclusions offered, although interestingly supported by several case-histories, are necessarily subjective and open to contention. The remainder of the
298 Enzyme Microb. Technol., 1979, vol. 1, October
University College Galway
Book reviews by Wang e t al. in 'Exploitation of Multienzyme Systems for Synthesis' and a more general survey is given by Sebek in 'Biotransformation of Steroid Hormones and Antibiotics'. The third part, 'Medical Applications of Proteins and Enzymes' opens unexpectedly with 'Zinc Biochemistry' by Vallee which, since it describes the role of zinc in normal and abnormal growth processes, holds a very tenuous claim to a place in this book. In 'Novel Applications for Antibodies' Arnon delineates the promising potential of antibodies as target-specific carriers of cytotoxic drugs, referring in particular to results obtained with andriamycin and daunomycin coupled to antibovine serum albumin and anti-B leukaemia. Realistically, the author remains aware that the ultimate limitation of this approach in cancer therapy may be the poor availability of suitable antibodies. The following three chapters all deal with various aspects of the medical application of immobilized enzymes. Hornby e t al. discuss 'Applications of Immobilized Enzymes in Analysis', but the chapter is disappointingly limited to the use of immobilized glucose dehydrogenase in the automated determination of blood glucose, and therefore gives a poor impression of the potential of immobilized enzymes in analysis. In 'Some Economic, Enzymological and Practical Problems in the Technological and Analytical Application of Immobilized Enzymes' Nelboeck, with insight, suggests that the present slow commercial application of immobilized enzymes may arise from the lack of attention given to improving their cost and practicability. Broun e t al. conclude this part with a concise review of 'Some Medical Applications of Immobilized Proteins and Enzymes'. The final part, 'Proteins as Food' is least diverse containing only two chapters, 'Interactions of Food Proteins with Water and with L i p i d s . . . ' by Karel and 'Muscle and Connective Tissue Proteins as Food' by Hultin. Both chapters emphasize protein chemistry rather than, as might be expected in this book, the application of plant and animal protein in engineered food products. Biotechnology embraces so many scientific disciplines that it is almost impossible for individuals to be fully acquainted with them all. On this basis 'Biotechnological Applications of Proteins and Enzymes' is recommended for its 'breadth' rather than its 'depth' of material; in general the chapters provide authoritative information but, more importantly, contain many references to important literature, so enabling the specialist research worker to keep abreast of developments within the full range of
disciplines which contribute to the progress of biotechnology. So far as non-specialist readership is concerned, the book is probably unsuitable for intense reading or study but adequately gives a global view of current work in the various fields covered.
V. VV. Pike John F. Kennedy
Immobilized EnzymesResearch and Development E d i t o r : I c h i r o Chibata
Kodansha Ltd, Japan, and John Wiley & Sons, New Y o r k L o n d o n - Sydney - T o r o n t o , 1978, 284 pp., £24.95, US $49.30
This book is edited by Ichiro Chibata, who is the Director of the Research Laboratory of Applied Biochemistry, Tanabe Seiyaku Co. Ltd. The other authors are Tetsuya Tosa, Tadashi Sato and Takao Mori, all of the same company, which developed the first industrial applications of immobilized enzymes and of immobilized cells. The introductory chapter is only eight pages long. This outlines the history of immobilized enzymes and then defines them together with immobilized cells. Chapter 2 is principally concerned with the methods of preparation of immobilized enzymes. Immobilization by physical adsorption and ionic binding are briefly considered. Covalent binding techniques are covered comprehensively with the chemistry being given in each case. Methods involving crosslinking and entrapping of the enzyme are also described. However, the useful method for immobilizing enzymes and cells which involves activation of supports by transition metal salts is not referred to. The chapter concludes with an important section, where the relationship between method of preparation and the characteristics of the immobilized enzyme are discussed, and short sections on methods used for immobilizing microbial cells and coenzymes. The properties of immobilized enzymes and, where appropriate, of microbial cells are described in chapter 3. Instances of altered enzyme specificity on immobilization due to the molecular size of the substrate are given. The temperature dependence of enzyme catalysed reactions are
covered. Unfortunately, the authors make use of the term 'optimum temperature' which is an arbitrary value, as pointed out by Dixon and Webb. Examples where changes of optimum pH, K m and Vmax occur on immobilization are given, together with probable explanations for the changes. There could have been a more detailed consideration of the several influences of the carrier on the progress of an immobilized enzyme catalysed reaction. The stability of immobilized enzymes is covered, although the importance of measuring operational stability should have been given more emphasis. The last and longest chapter is also the most interesting and original of the four. It deals with the applications of immobilized enzymes and microbial cells. After considering various aspects concerned with chemical engineering and immobilized systems, the authors go on to discuss chemical processes using them. These include important applications developed by the authors. The sections on analytical applications, medical applications and applications in food processing are informative but lack the same sense of involvement. There is also a section on affinity chromatography. The chapter concludes by considering the problems associated with the applications of immobilized enzymes, and also gives a list of their useful properties. The book cites over 1000 references and contains appendices. These are basically lists of commercially available water-insoluble carriers and immobilized enzymes, together with a list of manufacturers' names. The subject index is complemented by an enzyme index. I recommend this book as a useful introduction to, and survey of the subject of immobilized enzymes and microbial cells for chemists, biochemists and chemical engineers. However, the chemists could have hoped for more insight into which covalent methods of immobilization are most appropriate for commercial applications. The biochemist will be concerned that inhibition of immobilized enzymes is rarely mentioned and that the significance of various types of inhibition in the applications of immobilized enzymes is not discussed. Chemical engineers may be misled into believing that this aspect of the subject is still in its infancy and they will search in vain for the Michaelis-Menten equation. Perhaps all those engaged in the area covered by this book during the last 10 to 15 years should note that there are only five industrial processes utilizing immobilized enzymes and cells.
B. J. Gould
Enzyme Microb. Technol., 1979, vol. 1, October 299
and microbial technology having R&D facilities are few and far between, so that a link-up with industry is usually difficult in these areas. One possible solution now being tested by a group of individual researchers in University College, Galway, is the formation of a limited company as a vehicle for R&D
and eventual commercialization of ideas. It remains to be seen how this will develop, and it may be the subject of a further report in this column at a later date. D. B. Johnson
Biotechnological Applications of Proteins and Enzymes
book is conveniently divided into four main parts. The first part, 'The Production of Enzymes', although not encompassed by the book's title, nevertheless does provide a useful background to the central theme. Thus, 'Selection of Bacteria as Sources of Enzymes' by Hed6n features recent advances in the automatic mapping of the enzymatic potential of microorganisms and in computer-controlled steering of continuous cultures towards optimal production. Heden also rightfully stresses the increasing importance of microorganisms as an international resource. Aunstrup's contribution 'Industrial Approach to Enzyme Production', being mostly confined to enzyme production from microorganisms, is not as broadly based as its title suggests. Consequently, much material is repeated in the next chapter, 'The Microbial Production of Enzymes' by Solomons. However, other methods of enzyme production are covered in a balanced contribution on 'Production of Enzymes and Proteins in Tissue Culture', by Pye e t al. This chapter comprehensively reviews the increasingly acknowledged potential of tissue culture for the production of many biologically important compounds, including human insulin, interferon, growth hormone and hormonal glycoproteins (FSH, LH) which otherwise are difficult to obtain in quantity. The next and major part, 'Exploitation of Soluble and Insolubilized Enzymes', opens with 'Protein Insolubilization and Affinity Chromatography' by Porath and Caldwell. Recent developments by the authors and their collaborators in the use of chemically-modified dextran and agarose as supports for the chromatography of proteins, peptides and amino acids by reversible insolubilization are extensively reviewed. Several imaginative approaches to reversible protein insolubilization are described,
including hydrophobic affinity adsorption, charge-transfer adsorption and chelation to insolubilized metal ions. 'Industrial Application of Immobilized Enzymes: Present State of the Art' by Weetall covers both large- and small-scale applications in general. Since the industrial exploitation of immobilized enzymes is proving rather sluggish, this chapter holds few surprises. Unfortunately, some terms invoked by Weetall, for example 'half-life', have objectionable definition or application. As Lilly aptly points out in the following chapter, 'A Comparison of Ceils and Enzymes as Industrial Catalysts', many immobilized enzymes lose activity by non-first order processes and so the term 'half-life' should not be applied to them. Even so, this message remains unheeded in later chapters. In a diverse and interesting contribution, ' " T o getherness" through Immobilization', Mosbach describes catalytically efficient systems of immobilized enzyme and enzyme coenzyme combinations, and the analytical utility of these systems when in combination with electrodes or thermistors. Goldstein e t al. in 'Chemically Modified Polymers Containing lsocyanide Functional Groups as Supports for Enzyme Immobilization', illustrate the scope and versatility of the Passerini and four-component condensation reactions for the production of isocyanide groups in c o m m e r c i a l polymers and for the coupling of enzymes to such groups. The elimination of diffusion effects by pressure filtration through microporous enzymatic membranes is described in the only kinetics-based paper, 'Effectiveness of Enzyme membrane Filtration Reactors' by Simon e t al. Both the final contributions to this part discuss biotransformations. Thus, important examples of multienzyme syntheses, of the antibiotics f, ramicidin S and Bacitracin A, are thoroughly discussed
Editors: Zvi Bohak and Nathan Sharon Academic Press, New Y o r k San Francisco -- London, 1977, xliv + 367 pp., £21.60, US $33.00
Whereas its title is not incorrect, 'Biotechnological Applications of Proteins and Enzymes' is sufficiently broad yet progressive to rouse the inquisitorial instincts in biological chemists, biochemists and medical biochemists. Although the book is the outcome of a conference held in Israel in 1976 to honour the sixtieth birthday of Professor Ephraim KatchalskiKatzir, former President of the State of Israel, it is a collection of useful reviews rather than a conglomerate of highly specialized original research papers. These reviews cover a diversity, but not all aspects, of current and imminent applications of proteins etc. in industry, medicine and nutrition, and circumscribe the underlying technological and economic constraints of such applications. 'Biotechnological Applications of Proteins and Enzymes' opens with a biography describing Professor Katzir's pioneering work in the development of biotechnological applications of proteins and enzymes, and on his significant contributions to the scientific, educational and political life of Israel. Thereafter, Sir Ernst Chain discusses 'The Position of Applied Research in Non-industrial Laboratories'. The topic is 'too broad to be covered in one paper' and so the arguments presented and conclusions offered, although interestingly supported by several case-histories, are necessarily subjective and open to contention. The remainder of the
298 Enzyme Microb. Technol., 1979, vol. 1, October
University College Galway
Book reviews by Wang e t al. in 'Exploitation of Multienzyme Systems for Synthesis' and a more general survey is given by Sebek in 'Biotransformation of Steroid Hormones and Antibiotics'. The third part, 'Medical Applications of Proteins and Enzymes' opens unexpectedly with 'Zinc Biochemistry' by Vallee which, since it describes the role of zinc in normal and abnormal growth processes, holds a very tenuous claim to a place in this book. In 'Novel Applications for Antibodies' Arnon delineates the promising potential of antibodies as target-specific carriers of cytotoxic drugs, referring in particular to results obtained with andriamycin and daunomycin coupled to antibovine serum albumin and anti-B leukaemia. Realistically, the author remains aware that the ultimate limitation of this approach in cancer therapy may be the poor availability of suitable antibodies. The following three chapters all deal with various aspects of the medical application of immobilized enzymes. Hornby e t al. discuss 'Applications of Immobilized Enzymes in Analysis', but the chapter is disappointingly limited to the use of immobilized glucose dehydrogenase in the automated determination of blood glucose, and therefore gives a poor impression of the potential of immobilized enzymes in analysis. In 'Some Economic, Enzymological and Practical Problems in the Technological and Analytical Application of Immobilized Enzymes' Nelboeck, with insight, suggests that the present slow commercial application of immobilized enzymes may arise from the lack of attention given to improving their cost and practicability. Broun e t al. conclude this part with a concise review of 'Some Medical Applications of Immobilized Proteins and Enzymes'. The final part, 'Proteins as Food' is least diverse containing only two chapters, 'Interactions of Food Proteins with Water and with L i p i d s . . . ' by Karel and 'Muscle and Connective Tissue Proteins as Food' by Hultin. Both chapters emphasize protein chemistry rather than, as might be expected in this book, the application of plant and animal protein in engineered food products. Biotechnology embraces so many scientific disciplines that it is almost impossible for individuals to be fully acquainted with them all. On this basis 'Biotechnological Applications of Proteins and Enzymes' is recommended for its 'breadth' rather than its 'depth' of material; in general the chapters provide authoritative information but, more importantly, contain many references to important literature, so enabling the specialist research worker to keep abreast of developments within the full range of
disciplines which contribute to the progress of biotechnology. So far as non-specialist readership is concerned, the book is probably unsuitable for intense reading or study but adequately gives a global view of current work in the various fields covered.
V. VV. Pike John F. Kennedy
Immobilized EnzymesResearch and Development E d i t o r : I c h i r o Chibata
Kodansha Ltd, Japan, and John Wiley & Sons, New Y o r k L o n d o n - Sydney - T o r o n t o , 1978, 284 pp., £24.95, US $49.30
This book is edited by Ichiro Chibata, who is the Director of the Research Laboratory of Applied Biochemistry, Tanabe Seiyaku Co. Ltd. The other authors are Tetsuya Tosa, Tadashi Sato and Takao Mori, all of the same company, which developed the first industrial applications of immobilized enzymes and of immobilized cells. The introductory chapter is only eight pages long. This outlines the history of immobilized enzymes and then defines them together with immobilized cells. Chapter 2 is principally concerned with the methods of preparation of immobilized enzymes. Immobilization by physical adsorption and ionic binding are briefly considered. Covalent binding techniques are covered comprehensively with the chemistry being given in each case. Methods involving crosslinking and entrapping of the enzyme are also described. However, the useful method for immobilizing enzymes and cells which involves activation of supports by transition metal salts is not referred to. The chapter concludes with an important section, where the relationship between method of preparation and the characteristics of the immobilized enzyme are discussed, and short sections on methods used for immobilizing microbial cells and coenzymes. The properties of immobilized enzymes and, where appropriate, of microbial cells are described in chapter 3. Instances of altered enzyme specificity on immobilization due to the molecular size of the substrate are given. The temperature dependence of enzyme catalysed reactions are
covered. Unfortunately, the authors make use of the term 'optimum temperature' which is an arbitrary value, as pointed out by Dixon and Webb. Examples where changes of optimum pH, K m and Vmax occur on immobilization are given, together with probable explanations for the changes. There could have been a more detailed consideration of the several influences of the carrier on the progress of an immobilized enzyme catalysed reaction. The stability of immobilized enzymes is covered, although the importance of measuring operational stability should have been given more emphasis. The last and longest chapter is also the most interesting and original of the four. It deals with the applications of immobilized enzymes and microbial cells. After considering various aspects concerned with chemical engineering and immobilized systems, the authors go on to discuss chemical processes using them. These include important applications developed by the authors. The sections on analytical applications, medical applications and applications in food processing are informative but lack the same sense of involvement. There is also a section on affinity chromatography. The chapter concludes by considering the problems associated with the applications of immobilized enzymes, and also gives a list of their useful properties. The book cites over 1000 references and contains appendices. These are basically lists of commercially available water-insoluble carriers and immobilized enzymes, together with a list of manufacturers' names. The subject index is complemented by an enzyme index. I recommend this book as a useful introduction to, and survey of the subject of immobilized enzymes and microbial cells for chemists, biochemists and chemical engineers. However, the chemists could have hoped for more insight into which covalent methods of immobilization are most appropriate for commercial applications. The biochemist will be concerned that inhibition of immobilized enzymes is rarely mentioned and that the significance of various types of inhibition in the applications of immobilized enzymes is not discussed. Chemical engineers may be misled into believing that this aspect of the subject is still in its infancy and they will search in vain for the Michaelis-Menten equation. Perhaps all those engaged in the area covered by this book during the last 10 to 15 years should note that there are only five industrial processes utilizing immobilized enzymes and cells.
B. J. Gould
Enzyme Microb. Technol., 1979, vol. 1, October 299