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The PEP groups’s work on chitin, chitosan and chito-oligosaccharidesOBS Norwegians: For norsk-talende lesere og journalister: nedenfor vil dere vil finne flere linker til norske tekster, inklusive populærvitenskapelige tekster. We are interested in enzymes for processing of chitin and related polymers such as chitosan, a soluble, partially deacetylated form of chitin. These enzymes include family 18 chitinases, family 19 chitinases, chitosanases, chitin deacetylases and chitin synthases. We work on all of these except chitin synthases. We base our interest in these topics on several aspects of chitin and chitin enzymology: 1. A fundamental interest in how enzymes work and in enzyme engineering (enzyme improvement by rational design or screening of mutations). In this context, chitinases are a more or less “coincidental” choice. A new project on fundamental aspects of chitinases starts entitled “Applying advanced computational and experimental tools to explore surface electrostatics in chitinases” starts summer 2007 with one post-doc, Sigrid Gåseidnes (NFR funded). 2. Chitin turnover is an important process in nature. For example, such turnover is essential for growth of several plague organisms (fungi, nematodes, insects) and human pathogens. Also, chitinase activity in humans (i.e by human chitinases) is of great interest. Therefore, it is of great importance to understand how chitinases (and other chitin-modifying enzymes and non-catalytic proteins) work and to understand how inhibitors may be developed. Our collaborators in Dundee (Daan van Aalten et al.) are working very hard on chitinase inhibition. Our own work in this direction has so far been exclusively based on chito-oligosaccharides (CHOS – see point 3) as inhibitors or building blocks for inhibitors. A major part of this work is coordinated by Ass. Prof. Morten Sørlie at our institute, who just got funding from NFR for two researchers who will work on a project entitled “Environmentally friendly fungicides: combinatorial synthesis and screening of chitooligosaccharides”. Prof. Arne Tronsmo at our institute will start a new project, with one Ph.D. student (UMB funded), on the effect of chito-oligosaccharides on fungal growth in autumn 2007, in close collaboration with Morten Sørlie et al. and the PEP group. 3. Chitin is abundantly available, e.g. from the shelfish industry. We would like to devlop methods for valorization and exploitation of this valuable bioresource or its ”bulk” derivatives such as chitosan. This we aim at developing methods for converting chitin or chitosan to bioactive chito-oligosaccharides (CHOS), with the help of an enzyme “toolbox” consisting of (engineered) chitinases, chitosanases and deacetylases. We are interested in CHOS because they have many (potential) applications in addition to potentially being chitinase inhibitors. For example, CHOS may elicit plant defence responses and they may fullfil important signalling functions in humans. We are also interested in CHOS because we find the challenge of enzymatic “carbohydrate engineering” quite interesting. The work on CHOS production spans from identifying, characterizing and tailoring enzymes to more detailed work on CHOS synthesis and analysis. In addition commercial opportunities are explicitly addressed. The following people are involved:
4. Fundamentals of Biomass turnover. In 2005 & 2006 our work on chitin degradation has led to discoveries that are of general importance when it comes to understanding how enzymes manage to degrade recalcitrant polysaccharides. In 2005, we found a non-catalytic helper protein, CBP21, that acts synergistically with chitinases during chitin degradation, presumably by disrupting the substrate. In 2006 we made important discoveries concerning the role of processivity in chitin degradation. Both these topics are of major importance, not only for chitin degradation, but also for the degradation of other recalcitrant polysaccharides, in particular (ligno)cellulose. Particular interest comes from the bioethanol world: the development of second generation (lignocellulose-based) ethanol from woody materials relies on the availability of efficient enzyme technology for converting the robust starting material to fermentable sugar. Our findings on chitin degradation may help in the development of such technology. We have several types of projects in the field:
For more information and links concerning our activities in the bioethanol field, see here. Here you wil also find more information about our bioprospecting activities together with the Norwegian Forest and Landscape institute (”Skogoglandskap”). Note that a larger part on our work on chitin and CHOS is conducted in close collaboration with the group of Prof. Kjell M. Vårum at The Norwegian Biopolymer Laboratory, NOBIPOL, at NTNU, Trondheim. ARTICLES ON OUR CHITIN WORK, INTRODUCTORY TEXTS, AND LINKS TO BIOETHANOL
Do you want to know more details about the science? An overview of ongoing research projects, including some project summaries. |
