Role of Hydrodynamic Shear on Activity
and Structure of Proteins
C.B. Elias and J.B. Joshi
Department of Chemical Technology, University of Bombay, Matunga,
Mumbai-400 019, India
List of Symbols and Abbreviations ..................................
48
1 Introduction ..............................................
49
2 Deactivation Kinetics .........................................
50
3 Deactivation in Model Contactors .................................
53
3.1 Cylindrical Tubes .........................................
53
3.2 Concentric Cylinder Viscometer ................................
55
4 Deactivation in Unit Operations ..................................
57
4.1 Fermentation ...........................................
57
4.2 Cell Homogenization .......................................
59
4.3 Precipitation ............................................
61
4.4 Membrane Filtration .......................................
65
5 Role of Hydrodynamic Shear on the Structure of Proteins ...................
67
6 Conclusions and Perspectives ....................................
68
7 References ................................................
70
Proteins are important products used in industry. They may be enzymes which catalyze different
reactions or they may be required for their biological activities as hormones, growth factors or
therapeutics. During production and recovery, proteins are subjected to fluid forces which arise due
to operations such as stirring, pumping and centrifugation. The resulting hydrodynamic shear forces
may cause damage to the large molecular weight proteins, resulting in denaturation and inactivation
of the protein. This is a major concern as it affects the overall efficiency of protein recovery and final
yield of the product. A considerable amount of research has been devoted to studying the effects of
hydrodynamic shear stress on proteins, especially with respect to the enzymes. Enzymes are
subjected to shear stresses during their production in fermentors, during isolation and purification
steps in downstream operations and also during their use in enzyme reactors, especially if stirred
reactors are employed to perform enzyme catalysed reactions.
The present review discusses the effects of fluid shear stress on proteins including enzymes.
A brief description on deactivation has been included in order to understand the effect of shear on
the deactivation kinetics of proteins. The model systems used to subject proteins to shear and some
unit operations during protein processing or use wherein they are exposed to shear stresses have also
been presented. The significance of shear effects in designing bioprocesses involving shear sensitive
biocatalysts as well as suggestions for future work have also been given.
Advances in Biochemical Engineering/
Biotechnology, Vol. 59
Managing Editor: Th. Scheper
9 Springer-Verlag Berlin Heidelberg 1998
and Structure of Proteins
C.B. Elias and J.B. Joshi
Department of Chemical Technology, University of Bombay, Matunga,
Mumbai-400 019, India
List of Symbols and Abbreviations ..................................
48
1 Introduction ..............................................
49
2 Deactivation Kinetics .........................................
50
3 Deactivation in Model Contactors .................................
53
3.1 Cylindrical Tubes .........................................
53
3.2 Concentric Cylinder Viscometer ................................
55
4 Deactivation in Unit Operations ..................................
57
4.1 Fermentation ...........................................
57
4.2 Cell Homogenization .......................................
59
4.3 Precipitation ............................................
61
4.4 Membrane Filtration .......................................
65
5 Role of Hydrodynamic Shear on the Structure of Proteins ...................
67
6 Conclusions and Perspectives ....................................
68
7 References ................................................
70
Proteins are important products used in industry. They may be enzymes which catalyze different
reactions or they may be required for their biological activities as hormones, growth factors or
therapeutics. During production and recovery, proteins are subjected to fluid forces which arise due
to operations such as stirring, pumping and centrifugation. The resulting hydrodynamic shear forces
may cause damage to the large molecular weight proteins, resulting in denaturation and inactivation
of the protein. This is a major concern as it affects the overall efficiency of protein recovery and final
yield of the product. A considerable amount of research has been devoted to studying the effects of
hydrodynamic shear stress on proteins, especially with respect to the enzymes. Enzymes are
subjected to shear stresses during their production in fermentors, during isolation and purification
steps in downstream operations and also during their use in enzyme reactors, especially if stirred
reactors are employed to perform enzyme catalysed reactions.
The present review discusses the effects of fluid shear stress on proteins including enzymes.
A brief description on deactivation has been included in order to understand the effect of shear on
the deactivation kinetics of proteins. The model systems used to subject proteins to shear and some
unit operations during protein processing or use wherein they are exposed to shear stresses have also
been presented. The significance of shear effects in designing bioprocesses involving shear sensitive
biocatalysts as well as suggestions for future work have also been given.
Advances in Biochemical Engineering/
Biotechnology, Vol. 59
Managing Editor: Th. Scheper
9 Springer-Verlag Berlin Heidelberg 1998