Chemical Biology seminars

Sijbren Otto explores how features associated with life can arise from initially lifeless chemical components. The systems couple reversible oligomerization of comparatively simple molecular building blocks with self-assembly. Their behavior includes the spontaneous appearance of self-replicating molecules, catalytic activity extending beyond autocatalysis, and the breaking of chiral symmetry. These observations connect the emergence of molecular replication and catalysis with the origins of biological handedness.

Living systems select one molecular handedness, making the origin of homochirality a central problem in understanding how life began. David Lacoste examines how this asymmetry can emerge in autocatalytic chemical networks when they contain sufficiently many chiral species and operate far from equilibrium. Polymerization greatly expands molecular diversity, raising the question of whether it can also generate and preserve a preference for one handedness. The talk develops this connection through an RNA reactor model, studying the conditions under which template-directed ligation and polymerization produce and maintain homochirality.

Carolyn Bertozzi, Morten Meldal and Barry Sharpless explain the development of reliable reactions for connecting molecular components and the extension of those reactions into biological systems. Meldal and Sharpless describe the ideas and discoveries behind click chemistry, including efficient azide–alkyne coupling, and its use as a practical strategy for building functional molecules. Bertozzi addresses the additional challenge of performing chemical reactions in living systems without disrupting their normal processes. Her account connects the study and labelling of cell-surface glycans with the emergence of bioorthogonal chemistry and its biological and medical applications. The lectures distinguish robust synthetic coupling from the further requirements imposed by chemistry in cells and organisms.