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Publication Abstract from PubMed

Seven amino-acid substitutions introduced into the 343 amino-acid-long sequence of Coprinus cinereus peroxidase (CiP) led to a mutant enzyme (TS-rCiP) which is more stable than the native enzyme at higher temperature, pH and hydrogen peroxide concentrations. It is therefore more suitable for industrial applications. A structure determination was conducted on a deglycosylated but still active form of TS-rCiP based on X-ray diffraction data to 2.05 A resolution measured on a crystal cooled to 100 K and refined to R = 0.202 and R(free) = 0.249. The increased stability of the TS-rCiP enzyme can be understood from the structural changes of the TS-rCiP structure revealed by a comparative analysis with other known CiP structures. One of the more significant changes caused by three of the substitutions, I49S, V53A and T121A, is the conversion of a hydrophobic pocket into a hydrophilic pocket with associated changes in the water structure and the hydrogen-bonding interactions. The E239G substitution, which gives rise to increased thermostability at high pH, creates changes in the water structure and in the orientation of a phenylalanine (Phe236) in its vicinity. The three substitutions M166F, M242 and Y242F introduced to increase the oxidative stability do not introduce any structural changes.

The structure of a mutant enzyme of Coprinus cinereus peroxidase provides an understanding of its increased thermostability.,Houborg K, Harris P, Poulsen JC, Schneider P, Svendsen A, Larsen S Acta Crystallogr D Biol Crystallogr. 2003 Jun;59(Pt 6):997-1003. Epub 2003, May 23. PMID:12777761^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.