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KOÇ UNIVERSITY PHYSICS SEMINAR
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Speaker : Alkan Kabakçıoğlu, Koç University
Title : DNA folding thermo/dynamics (a topology-induced Bose-Einstein condensate?)
Date : December 19, 2017 Tuesday
Time : 2:30 P.M.
Cookie & Tea : SCI 103 2:15 P.M.
Place : SCI 103
web : https://physics-seminars.ku.
Abstract:
DNA denaturation is possibly one of the earliest problems in biophysics that grabbed the attention of statistical physicists. The nature of the folding/melting transition has been subject to debate since 60’s until a breakthrough in the past decade mostly settled the question. We recently readdressed the problem under the condition of fixed linking number (nonzero due to the helical structure and topologically conserved for circular DNAs or plasmids) and found that the melting behavior is qualitatively different from that of the unconstrained DNA with freely dangling ends. In particular we argue, by generalizing the predominant theoretical model in this field, that the transition rigorously follows an “inverted” BEC scenario where a macroscopic loop appears at Tc and grows steadily with increasing temperature. I will also discuss our recent findings on hairpin folding dynamics which further underline the relevance of helicity in DNA’s structural transitions.
Bio: Dr. Kabakcioglu is a statistical physicist whose research is situated at the interface of physics with biology. He received his undergraduate and M.Sc. degrees from Bilkent University, Turkey in electrical engineering (1990) and theoretical physics (1993), respectively. After completing his Ph.D. work in statistical physics of random systems at Massachusetts Institute of Technology (1999), he did postdoctoral studies on physics of biomolecules at Weizmann Institute of Science and Padova University. Since 2005, he is a faculty member in the department of physics at Koc University, Istanbul. Dr. Kabakcioglu’s recent research interests include organization principles of complex networks and non/equilibrium aspects of biopolymer physics.