Prof. Dr. Semra KOCABIYIK

Middle East Technical University, Department of Biological Sciences, 06800 Ankara/TURKEY

Office Room: 139

Tel: +90 312 210 5174

Fax: +90 312 210 7976

E - Mail: biosemra[-at-]metu.edu.tr


Education: BS and MS: Univ. Ankara, Facult. Agricult., MS: Dept. Biol., METU.
Ph.D: Dept.Biol. METU.
Post-Doctoral Assoc: Univ. Louisville, Kentucky, USA.

Research Interest: Structure / function analysis of thermostable proteins ( models: citrate synthase, antibiotic resistance enzymes); molecular biology of energy dependent progressive and programmed proteolysis; heat-shock response in thermohilic archaea.

Description of research activities: 1. uncover molecular mechanisms underlying protein themostability by using genetic and protein engineering techniques,

2. genetic, functional and regulatory analysis of molecular chaperones (Hsp60, sHsp) and programmed proteolysis by proteasomes (model system: thermophilic archaeon Thermoplasma volcanium),

3. applications of principles from structure /function analyses of enzymes for improvement and design of biomolecules.

Selected Publications:

S. Kocabıyık and S. Aygar. Improvement of protein stability and enzyme recovery under stress conditions by using a small SHP (tpv-HSP 14.3) form Thermoplasma volcanium. Process Biochemistry, 47: 1676-1683, 2012

S. Kocabıyık et al., Molecular cloning and co-expression of Thermoplasma volcanium proteasome subunit genes. Protein Expression and Purification, 73 : 223–230, 2010.

S. Kocabıyık. Essential Structural and Functional Features of Small Heat Shock Proteins in Molecular Chaperoning Process. Protein & Peptide Letters, 16, 613-622, 2009.

S. Kocabıyık, B. Demirok. Cloning and overexpression of a thermostable signal peptide peptidase (SppA) from Thermoplasma volcanium GSS1 in E.coli. Biotechnology Journal, 4(7): 1055-1065, 2009

S. Kocabıyık and H.Ozel. An Extracellular pepstatin insensitive acid protease produced by Thermoplasma volcanium. Bioresource Technology, 98: 112-117, 2007.

S. Kocabıyık and İ.Özdemir. Purification and Characterization of an intracellular Chymotrypsin-Like Serine Protease from Thermoplasma volcanium. Bioscience, Biotechnology and Biochemistry. 70(1):126-134, 2006.

S. Kocabıyık and B.Erdem : Intracellular Alkaline Proteases Produced by Thermoacidophiles. Detection of Protease Heterogeneity by Gelatin Zymography and Polymerase Chain Reaction (PCR). Bioresource Technology, 84:29-33, 2002.

S. Kocabıyık and I.Erduran. The Effect of Valine Substitution for Glycine in the Dimer Interface of Citrate Synthase from Thermoplasma acidophilum on Stability and Activity. Biochem. Biophys. Res. Commun., 275:460-465, 2000.

Erduran, S. Kocabıyık. Amino acid substitutions in the subunit interface enhancing thermostability of Thermoplasma acidophilum citrate synthase. Biochem. Biophys. Res. Commun., 249: 566-571, 1998.

Graduate program affiliation: Biology, Biochemisrty, Biotechnology, Biomedical Engineering