Chemical Probes to Study Fucosylated Glycans

Citation

Krishnamurthy, Chithra (2013) Chemical Probes to Study Fucosylated Glycans. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/Z99021SG. https://resolver.caltech.edu/CaltechTHESIS:06052013-123658997

Abstract

Fucosylated glycans have many critical biological roles, from leukocyte adhesion to host-microbe interactions. However, a molecular level understanding of these sugars has been lacking, in part due to the chemical and structural diversity of glycans that make them challenging to study. In order to gain a deeper understanding of fucosylated glycans, we have explored the use of chemical probes to study these structures. In Chapters 1 and 2, we apply a metabolic labeling technique for the investigation of fucosylated glycans in neurons, where they have been implicated in learning and memory processes. However, the molecular mechanisms by which these sugars influence neuronal processes are not well understood, and only a handful of fucosylated glycoproteins have been identified. In order to facilitate our understanding of these processes, we exploit non-natural fucose analogs to identify the fucose proteome in rat cortical neurons, identifying proteins involved in cell adhesion, neuronal signaling, and synaptic transmission. Moreover, we track fucosylated glycoproteins in hippocampal neurons, and show that fucosylated glycoproteins localize to the Golgi, axons, and dendrites, and are enriched in synapses. In Chapter 4, we report a new chemoenzymatic strategy for the sensitive detection of the Fucα(1-2)Gal epitope, which has been implicated in tumorigenesis as a potential biomarker of cancer progression. We demonstrate that the approach is highly selective for the Fucα(1-2)Gal motif, detects a variety of complex glycans and glycoproteins, and can be used to profile the relative abundance of the motif on live cells, discriminating malignant from normal cells. These approaches represent new potential applications and strategies for the investigation of fucosylated glycans, and expand the technologies available for understanding the roles of this important class of carbohydrates in physiology and disease.

Thesis Files