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

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.

Department Of Biotechnology

Biotechnology and Bioprocess Engineering

What is the role of thermodynamics on protein stability?

The critical parameters, such as slant age, mycelium age and contact time of mycelium with lytic enzymes which affects the formation of protoplast from the Penicillium griseofulvum mycelium were studied using a novel technique called response surface methodology. The design used to optimize these parameters was full factorial central composite design. The number of protoplasts, viability of protoplasts and griseofulvin yield are the three responses studied in this communication. The individual optimum values of slant age, inoculum age and contact time obtained are 187.1, 30.81, 21.4 h, respectively, for number of protoplast/ml 68.92, 33.01, 9.88 h, respectively, for percentage viability of protoplasts and 230.2, 73.6, 31.2 h, respectively, for griseofulvin. In order to obtain a single optimum value for all the three responses, a multi-response analysis was carried out using a generalized distance approach. The simultaneous optimum values of slant age, inoculum age and contact time are 133.78, 37.1 and 15.97 h, respectively, for all the three responses. © 2003 Elsevier Science B.V. All rights reserved.

GENERAL

Department Of Chemical Engineering

Biochemical Engineering Journal

Statistical analysis on some critical parameters affecting the formation of protoplasts from the mycelium of Penicillium griseofulvum

Pectinases are a complex group of enzymes that degrade various pectic substances present in plant tissues. Pectinases have potential applications in fruit, paper and textile industries. Apart from these industrial applications, these enzymes possess biological importance in protoplast fusion technology and plant pathology. Since applications of pectinases in various fields are widening, it is important to understand the nature and properties of these enzymes for efficient and effective usage. For the past few years, vigorous research has been carried out on isolation and characterization of pectinases. New affinity matrices with improved characteristics and affinity-precipitation techniques have been developed for purification of pectinases. Recently much attention has been focused on chemical modification of pectinases and their catalytic performance by various researchers. These studies are helpful in determining key amino acid residues responsible for substrate binding, catalytic action, and physico-chemical environmental conditions for maximum hydrolysis. This short review highlights progress on purification and understanding the biochemical aspects of microbial pectinases. © 2002 Elsevier Science Ltd. All rights reserved.

Process Biochemistry

Purification and biochemical properties of microbial pectinases - A review

Methods in molecular biology (Clifton, N.J.)

Reconstitution and assay of biogenic membrane-derived phospholipid flippase activity in proteoliposomes.

Enzyme kinetics data play a vital role in the design of reactors and control of processes. In the present study, kinetic studies on pectinases were carried out. Partially purified polymethylgalacturonase (PMG) and polygalacturonase (PG) were the two pectinases studied. The plot of initial rate vs. initial substrate concentration did not follow the conventional Michaelis-Menten kinetics, but substrate inhibition was observed. For PMG, maximum rate was attained at an initial pectin concentration of 3 g/l, whereas maximum rate was attained when the initial substrate concentration of 2.5 g/l of polygalacturonic acid for PG I and PG II. The kinetic data were fitted to five different kinetic models to explain the substrate inhibition effect. Among the five models tested, the combined mechanism of protective diffusion limitation of both high and inhibitory substrate concentrations (semi-empirical model) explained the inhibition data with 96-99% confidence interval.

Journal of Microbiology and Biotechnology

Analysis of kinetic data of pectinases with substrate inhibition

Bioresource Technology

Studies on the removal of dyes from a synthetic textile effluent using barley husk in static batch mode and in continuous flow packed bed reactor

Phospholipid translocation (flip-flop) across membrane bilayers is typically assessed via assays utilizing partially water-soluble phospholipid analogs as transport reporters. These assays have been used in previous work to show that phospholipid translocation in biogenic (self-synthesizing) membranes such as the endoplasmic reticulum is facilitated by specific membrane proteins (flippases). To extend these studies to natural phospholipids while providing a framework to guide the purification of a flippase, we now describe an assay to measure the transbilayer translocation of dipalmitoylphosphatidylcholine, a membrane-embedded phospholipid, in proteoliposomes generated from detergent-solubilized rat liver endoplasmic reticulum. Translocation was assayed using phospholipase A2 under conditions where the vesicles were determined to be intact. Phospholipase A2 rapidly hydrolyzed phospholipids in the outer leaflet of liposomes and proteoliposomes with a half-time of ∼0.1 min. However, for flippase-containing proteoliposomes, the initial rapid hydrolysis phase was followed by a slower phase reflecting flippase-mediated translocation of phospholipids from the inner to the outer leaflet. The amplitude of the slow phase was decreased in trypsin-treated proteoliposomes. The kinetic characteristics of the slow phase were used to assess the rate of transbilayer equilibration of phospholipids. For 250-nm diameter vesicles containing a single flippase, the half-time was 3.3 min. Proportionate reductions in equilibration half-time were observed for preparations with a higher average number of flippases/vesicle. Preliminary purification steps indicated that flippase activity could be enriched ∼15-fold by sequential adsorption of the detergent extract onto anion and cation exchange resins.

World University root node

Fulltext

Journal of Biological Chemistry

Transbilayer movement of dipalmitoylphosphatidylcholine in proteoliposomes reconstituted from detergent extracts of endoplasmic reticulum: Kinetics of transbilayer transport mediated by a single flippase and identification of protein fractions enriched in flippase activity

Journal of Industrial Microbiology and Biotechnology

Conversion of g butyrobetaine to L-carnitine by Achromobacter cycloclast

Bioprocess Engineering

Microbial and Enzymatic synthesis of L-Carnitine

Bioprocess En

Rotating simplex method of optimization of physical parameters for higher production of extracellular pectinases in bioreactor

Enzyme and Microbial Technology

Performance of pectolytic enzymes during hydrolysis of pectic substances under assay conditions: A statistical approach

Behaviour of pectinases under process conditions

Multiresponse analysis of microbiological parameters affecting the production of pectolytic enzymes: a statistical view

Production of pectolytic enzymes - a review

Pectolytic enzymes, viz., polymethylgalacturonase, polygalacturonase and pectinlyase were synthesised by Aspergillus niger NCIM 548 using submerged cultivation. The combined effect of pH and temperature on these enzymes was studied using response surface methodology. A central composite design for two variables was employed to study the combined effect of pH and temperature on stability. The optimum pH and temperature were found to be 2.23 and 23°C respectively for polymethylgalacturonase; 4.8 and 28°C respectively for polygalacturonase and 3.9 and 29°C respectively for pectinlyase. It has also been found that pectinlyase is more thermostable than other two enzymes. © 1998 Elsevier Science S.A. All rights reserved.

Application of response surface methodology to evaluate some aspects on stability of pectolytic enzymes from Aspergillus niger

Bioprocess optimization- A challenge

Optimisation of physical parameters pH and temperature for maximised activity and stability of Vibrio cholerae L-asparaginase by statistical experimental design