THREE DIMENSIONAL STRUCTURE PREDICTION OF PANOMYCOCIN, A NOVEL EXO-BETA-1,3-GLUCANASE ISOLATED FROM WICKERHAMOMYCES ANOMALUS NCYC 434 AND COMPUTATIONAL SITE-DIRECTED MUTAGENESIS STUDIES TO ENHANCE ITS THERMAL STABILITY


MUHAMMED M. T. , İzgü F., Son Ç. D.

5th International Conference on Computation for Science and Technology, Antalya, Turkey, 23 - 26 September 2018, pp.67

  • Publication Type: Conference Paper / Summary Text
  • City: Antalya
  • Country: Turkey
  • Page Numbers: pp.67

Abstract

Panomycocin is a naturally produced patent antimycotic/antifungal protein secreted by the yeast Wickerhamomyces anomalus NCYC 434 with an exo-beta-1,3-glucanase activity. It has lethal effect on fungi by hydrolyzing beta-1,3-glucan residues of the cell wall of sensitive fungal cells and causes loss of cell wall rigidity which leads to cell death due to the osmotic pressure. Since panomycocin is sensitive to heat like the other yeast killer proteins, enhancement of its thermal stability is crucial. In this study the three dimensional structure of panomycocin was predicted and the computational site-directed mutagenesis was performed to enhance its thermal stability over the body temperature for topical therapeutic applications. Homology modeling was performed with MODELLER and I-TASSER. The reliability of the model was confirmed with ERRAT, Verify 3D and Ramachandran plot values. Enhancement of the thermal stability of the model was done using contemporary servers and programs as SPDBViewer, CNA, I-Mutant2.0, Eris, AUTO-MUTE and MUpro. In the region outside the binding site of the model Leu52Arg, Phe223Arg and Gly254Arg were found to be the best thermostabilizing mutations with 6.26 K, 6.26 K and 8.27 K increases respectively. in the binding site Glu186Arg was found to be the best thermostabilizer mutation with a 9.58 K temperature increase. The results obtained in this study led us to design a mutant panomycocin that can be used as a novel antimycotic/antifungal drug in a liquid formulation for topical applications over the normal body temperature. Furthermore, these methods can be used in future studies for the detection of amino acid point mutations that could increase the thermal stability of similar proteins.