Dear Colleagues and Students,
You are cordially invited to attend the seminar organized by the Department of MBG.
Title: “Learning from nature: establishment of a library of natural and rationally designed hydrophobins from Trichoderma spp. with diverse surface activity”
Speaker: Assoc. Prof. Gunseli Bayram Akcapinar
Time: May 8, Wednesday at 15:40
Host: Bahar Değirmenci Uzun
Abstract: Hydrophobins (HFBs) are the small, secreted cysteine rich, amphiphilic proteins which exhibit high surface activities. They are mainly produced by fungi. Their ability to self-assemble at hydrophobic/hydrophilic interfaces makes them ideal candidates for a diversity of industrial applications. In this study, two complementary approaches were used for the construction of a library of HFB4 proteins from a diverse array of Trichoderma species. In the first approach, positive evolution, structure guided protein engineering was employed to generate five mutants of HFB4 from T. virens using a newly identified repertoire of 160 orthologous genes encoding a novel HFB4 in different species of Trichoderma. Molecular Dynamics simulations were performed to decipher the functionally important residues and to study the effects of proposed mutations. In the second approach, eight different natural HFB4 orthologues exhibiting diverse properties were selected from the newly identified repertoire of Trichoderma species based on pI and hydrophobicity using bioinformatics methods. Natural and tailor-made HFB4s were heterologously expressed in Pichia pastoris. A collection of biochemical and biophysical techniques were employed to verify the expression and surface activity of these proteins and to analyse the differences in the surface activity. Three mutants of HFB4vir were found to exhibit improved surface activity on glass. All HFB4 orthologues were shown to increase the water contact angle (WCA) of the glass to different extents. Two HFB4 orthologues, HFB4kon and HFB4est, exhibited the highest surface activity on glass by increasing the WCA by almost 70° and 40°, respectively.
All interested are cordially invited.