*All are invited to attend this week's Bioinformatics Colloquium Hosted by Prof. Jeff Solka Tuesday Nov. 20 4:30-6:00 p.m. at the PW campus, Bull Run Hall #248 Guest speaker is Dr. Amarda Shehu from Mason's Computer Science Dept.* Title: Probabilistic Search Frameworks for Protein Modeling Abstract: Protein modeling is central to improve our understanding of biology and disease. Diverse search and optimization algorithms in robotics motion planning and evolutionary computation bear useful analogies and ideas that can be exploited to advance the state of protein modeling. Building on these analogies, we present novel probabilistic search and optimization algorithms to compute the biologically-active structure of a protein from its amino acid sequence, model the bound structure of a protein dimer from the unbound rigid monomeric structures, or map conformational transitions between two functionally-relevant structural states of a protein system. In particular, a novel robotics-inspired probabilistic search framework is shown versatile and effective both in modeling structures and transitions between them. The framework employs projections of the search space in order to adaptively guide its exploration and further computational resources to relevant regions of the search space. Applications show enhanced sampling of the protein conformational space and effective modeling of biologically-active structures. Conformational transitions are obtained that connect functional states of significant structural dissimilarity in multimodal protein systems. A novel evolutionary-inspired probabilistic optimization framework is shown effective in sampling minima of an energy surface. Moreover, ongoing work is showing that utilization of both the evolutionary and robotics-inspired framework allows obtaining a broad view of the energy surface of small peptides and mapping out transitions between stable and semi-stable states. ###