The most challenging and emerging field of biotechnology is the tailoring of proteins to attain the desired characteristic properties. In order to increase the stability of proteins and to study the function of proteins, the mechanism by which proteins fold and unfold should be known. It has been debated for a long time how exactly the linear form of a protein is converted into a stable 3-dimensional structure. The literature showed that many theories support the fact that protein folding is a thermodynamically controlled process. It is also possible to predict the mechanism of protein deactivation and stability to an extent from thermodynamic studies. This article reviewed various theories that have been proposed to explain the process of protein folding after its biosynthesis in ribosomes. The theories of the determination of the thermodynamic properties and the interpretation of thermodynamic data of protein stability are also discussed in this article. ©KSBB.

Sathyanarayana Naidu Gummadi

Department Of Biotechnology

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

What is the role of thermodynamics on protein stability

Biotechnology and Bioprocess Engineering

Enzymes are deactivated by different ways to an inactive state, which is a major constraint in the development of biotechnological processes. Understanding the complex process of enzyme deactivation will be helpful in enhancing the feasibility of many biological processes. This paper mainly deals with the different ways by which enzymes are inactivated, which includes the role of thermodynamics in deactivation. Different models namely, unified deactivation theory, single exponential model, rapid equilibrium model, isozyme model and bacterial contamination model used to describe the complex deactivation processes are also discussed in this communication. The complete understanding of deactivation process is very essential in commercialization because enzyme activity and stability of the enzyme play a critical role in economics of biotechnological processes. Activity and stability of the enzyme are conflicting properties and trade-off between these factors must be considered in the selection and design of enzymes.

Bioprocess Engineering

Enhancing the feasibility of many biotechnological processes through enzyme deactivation studies

The combined effect of pH and temperature on chitinase was investigated using response surface methodology. A central composite design for two variables was employed. The optimal pH and temperature for the least degree of deactivation were found out to be 5.4 and 24°C respectively. The deactivation rate constants and the half life of chitinase were estimated at different pH and temperature combinations. At the optimal pH of 5.4, the rate of the deactivation was found to be the least. Thermodynamic parameters, viz., ΔH*, ΔS*, ΔG* and activation energy of thermal deactivation of chitinase were calculated in the temperature range from 50°C to 60°C.

Journal	Biotechnology and Bioprocess Engineering
Publisher	Korean Society for Biotechnology and Bioengineering
ISSN	12268372
Open Access	No