Development of transition state analogues targeting chitinases and oligosaccharyl transferase

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 2006.

Bibliographic Details
Main Author: Choi, Seungjib
Other Authors: Barbara Imperiali.
Format: Thesis
Language:eng
Published: Massachusetts Institute of Technology 2007
Subjects:
Online Access:http://hdl.handle.net/1721.1/37694
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author Choi, Seungjib
author2 Barbara Imperiali.
author_facet Barbara Imperiali.
Choi, Seungjib
author_sort Choi, Seungjib
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description Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 2006.
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spelling mit-1721.1/376942019-04-12T14:31:03Z Development of transition state analogues targeting chitinases and oligosaccharyl transferase Choi, Seungjib Barbara Imperiali. Massachusetts Institute of Technology. Dept. of Chemistry. Massachusetts Institute of Technology. Dept. of Chemistry. Chemistry. Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 2006. Vita. Includes bibliographical references. Oligosaccharyl transferase (OT) plays a central role in the biosynthesis of asparagine-linked glycoproteins in eukaryotic systems. The glycosylation step catalyzed by OT involves the co-translational transfer of a tetradecasaccharide from a dolichyl-pyrophosphate carrier to an asparagine side-chain within the Asn-Xaa-Ser/Thr sequence of a nascent polypeptide. Chitinases, which was emerged as a therapeutic target in combating asthma, are [beta]-1,4-N-acetylglucosaminidases that hydrolyze chitin to generate the disaccharide chitobiose Although the reactions catalyzed by the two enzymes follow different pathways, they are believed to share similar transition states involving an oxocarbenium ion. To understand the mechanism of OT and discover potent and selective inhibitors against different chitinases, our intent was to utilize the common transition state analogue for both enzymes and systematically introduce additional binding determinants. The pseudo-disaccharides containing an imino sugar were designed to target the oxocarbenium ion like transition state. The pseudo-disaccharides containing imino sugar were synthesized and evaluated at inhibitors for OT and chitinases. (cont.) Highlights and supporting studies from this work include: (1) the use of the Amadori rearrangement to generate the acyclic substrate; (2) the glycosylation of [beta]-hydroxy ketone; (3) the intramolecular reductive amination between the in-situ generated amine from azido and ketone moieties; (4) the determination of the stereo-chemical outcome by NOE difference experiments. The pseudo-disaccharides containing imino sugars exhibited IC50s in the low micromolar range versus chitinase, yet significant inhibitory activity against OT was not observed. by Seungjib Choi. Ph.D. 2007-06-28T12:24:39Z 2007-06-28T12:24:39Z 2006 2006 Thesis http://hdl.handle.net/1721.1/37694 131203686 eng M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission. http://dspace.mit.edu/handle/1721.1/7582 158, A1-A34, [1] leaves application/pdf Massachusetts Institute of Technology
spellingShingle Chemistry.
Choi, Seungjib
Development of transition state analogues targeting chitinases and oligosaccharyl transferase
title Development of transition state analogues targeting chitinases and oligosaccharyl transferase
title_full Development of transition state analogues targeting chitinases and oligosaccharyl transferase
title_fullStr Development of transition state analogues targeting chitinases and oligosaccharyl transferase
title_full_unstemmed Development of transition state analogues targeting chitinases and oligosaccharyl transferase
title_short Development of transition state analogues targeting chitinases and oligosaccharyl transferase
title_sort development of transition state analogues targeting chitinases and oligosaccharyl transferase
topic Chemistry.
url http://hdl.handle.net/1721.1/37694
work_keys_str_mv AT choiseungjib developmentoftransitionstateanaloguestargetingchitinasesandoligosaccharyltransferase