<?xml version="1.0" encoding="UTF-8"?><?xml-stylesheet type="text/xsl" href="static/style.xsl"?><OAI-PMH xmlns="http://www.openarchives.org/OAI/2.0/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/ http://www.openarchives.org/OAI/2.0/OAI-PMH.xsd"><responseDate>2026-09-19T20:40:15Z</responseDate><request verb="GetRecord" identifier="oai:dspace.mit.edu:1721.1/28701" metadataPrefix="dim">https://dspace.mit.edu/server/oai/request</request><GetRecord><record><header><identifier>oai:dspace.mit.edu:1721.1/28701</identifier><datestamp>2022-01-13T07:54:21Z</datestamp><setSpec>com_1721.1_7582</setSpec><setSpec>com_1721.1_7581</setSpec><setSpec>col_1721.1_131022</setSpec></header><metadata><dim:dim xmlns:dim="http://www.dspace.org/xmlns/dspace/dim" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:doc="http://www.lyncode.com/xoai" xsi:schemaLocation="http://www.dspace.org/xmlns/dspace/dim http://www.dspace.org/schema/dim.xsd">
   <dim:field mdschema="dc" element="contributor" qualifier="advisor" lang="en_US">Peter H. Seeberger.</dim:field>
   <dim:field mdschema="dc" element="contributor" qualifier="author" lang="en_US">Ratner, Daniel Martin, 1977-</dim:field>
   <dim:field mdschema="dc" element="contributor" qualifier="other" lang="en_US">Massachusetts Institute of Technology. Dept. of Chemistry.</dim:field>
   <dim:field mdschema="dc" element="contributor" qualifier="department">Massachusetts Institute of Technology. Department of Chemistry</dim:field>
   <dim:field mdschema="dc" element="date" qualifier="accessioned">2005-09-27T17:51:40Z</dim:field>
   <dim:field mdschema="dc" element="date" qualifier="available">2005-09-27T17:51:40Z</dim:field>
   <dim:field mdschema="dc" element="date" qualifier="copyright" lang="en_US">2004</dim:field>
   <dim:field mdschema="dc" element="date" qualifier="issued" lang="en_US">2004</dim:field>
   <dim:field mdschema="dc" element="identifier" qualifier="uri">http://hdl.handle.net/1721.1/28701</dim:field>
   <dim:field mdschema="dc" element="identifier" qualifier="oclc" lang="en_US">59133183</dim:field>
   <dim:field mdschema="dc" element="description" lang="en_US">Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 2004.</dim:field>
   <dim:field mdschema="dc" element="description" lang="en_US">Vita.</dim:field>
   <dim:field mdschema="dc" element="description" lang="en_US">Includes bibliographical references.</dim:field>
   <dim:field mdschema="dc" element="description" qualifier="abstract" lang="en_US">(cont.) 2G12, cyanovirin-N, and a recently identified anti-HIV protein, scytovirin.</dim:field>
   <dim:field mdschema="dc" element="description" qualifier="abstract" lang="en_US">Glycosylation is critical to cellular function in eukaryotic systems. N-linked modification of asparagine residues within nascent proteins is involved in numerous folding and processing pathways. N-linked glycans are also a common feature of viral-associated envelope glycoproteins, including gpl20 and gp41 of the human immunodeficiency virus (HIV-1). These glycans are attractive targets for therapy and prophylaxis due to their numerous roles in HIV infectivity and immunoevasion. This thesis describes the solution-phase synthesis of a series high-mannose type glycans using a linear synthetic approach. The synthetic mannans are used to study the potent anti-HIV microbicide cyanovirin-N, a novel 11 kDa protein isolated from the cyanobacterium (blue-green algae) Nostoc ellipsosporum. These studies established the structural basis for carbohydrate-binding by cyanovirin-N, which is responsible for its HIV inactivating properties. Automated solid-phase synthesis and microfluidic reactors were employed in the development of new technologies for synthetic carbohydrate chemistry. Utilizing a carbohydrate synthesizer, the first automated solid-phase synthesis of the N-linked core pentasaccharide is detailed. In addition, the design, fabrication and application of a microreactor for optimizing the glycosylation reaction is described. Utilizing a novel tri(ethylene glycol) linker with a reactive thiol handle, the fabrication of carbohydrate microarrays is depicted. A panel of oligosaccharides was selected to represent the major structural determinants of high-mannose type glycans on a single microarray. These microarrays were used study the glycan-dependent binding interactions of four gpl20-binding proteins: the dendritic cell lectin DC-SIGN, the antibody</dim:field>
   <dim:field mdschema="dc" element="description" qualifier="statementofresponsibility" lang="en_US">by Daniel Martin Ratner.</dim:field>
   <dim:field mdschema="dc" element="description" qualifier="degree" lang="en_US">Ph.D.</dim:field>
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   <dim:field mdschema="dc" element="publisher" lang="en_US">Massachusetts Institute of Technology</dim:field>
   <dim:field mdschema="dc" element="rights" lang="en_US">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.</dim:field>
   <dim:field mdschema="dc" element="rights" qualifier="uri">http://dspace.mit.edu/handle/1721.1/7582</dim:field>
   <dim:field mdschema="dc" element="subject" lang="en_US">Chemistry.</dim:field>
   <dim:field mdschema="dc" element="title" lang="en_US">Solution-phase and automated solid-phase synthesis of high-mannose oligosaccharides : application to carbohydrate microarrays and biological studies</dim:field>
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   	&lt;Title>Solution-phase and automated solid-phase synthesis of high-mannose oligosaccharides : application to carbohydrate microarrays and biological studies&lt;/Title>
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   	&lt;PublicationDate>2004&lt;/PublicationDate>
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        	&lt;DisplayName>Ratner, Daniel Martin, 1977-&lt;/DisplayName>
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    &lt;Keyword>Chemistry.&lt;/Keyword>
   	&lt;Abstract>(cont.) 2G12, cyanovirin-N, and a recently identified anti-HIV protein, scytovirin.&lt;/Abstract>
   	&lt;Abstract>Glycosylation is critical to cellular function in eukaryotic systems. N-linked modification of asparagine residues within nascent proteins is involved in numerous folding and processing pathways. N-linked glycans are also a common feature of viral-associated envelope glycoproteins, including gpl20 and gp41 of the human immunodeficiency virus (HIV-1). These glycans are attractive targets for therapy and prophylaxis due to their numerous roles in HIV infectivity and immunoevasion. This thesis describes the solution-phase synthesis of a series high-mannose type glycans using a linear synthetic approach. The synthetic mannans are used to study the potent anti-HIV microbicide cyanovirin-N, a novel 11 kDa protein isolated from the cyanobacterium (blue-green algae) Nostoc ellipsosporum. These studies established the structural basis for carbohydrate-binding by cyanovirin-N, which is responsible for its HIV inactivating properties. Automated solid-phase synthesis and microfluidic reactors were employed in the development of new technologies for synthetic carbohydrate chemistry. Utilizing a carbohydrate synthesizer, the first automated solid-phase synthesis of the N-linked core pentasaccharide is detailed. In addition, the design, fabrication and application of a microreactor for optimizing the glycosylation reaction is described. Utilizing a novel tri(ethylene glycol) linker with a reactive thiol handle, the fabrication of carbohydrate microarrays is depicted. A panel of oligosaccharides was selected to represent the major structural determinants of high-mannose type glycans on a single microarray. These microarrays were used study the glycan-dependent binding interactions of four gpl20-binding proteins: the dendritic cell lectin DC-SIGN, the antibody&lt;/Abstract>
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