We thank Zehavit Frenkel and Sandra Tolchinsky for technical assistance. Research related to this work is supported by grants from the Israel Science Foundation (1229/07) and German-Israeli Project Cooperation (DIP-DFG).

The following protocol is intended for analysis of sugar chains of total glycoproteins or of a specific glycoprotein of interest. The procedure is basically the same for both cases with a few alterations as stated throughout the protocol.
<ol>
 <li> For metabolic labeling of N-linked glycans one needs to use a subconfluent culture of mammalian cells grown overnight in a 90 mm dish for each sample (samples may represent different time points or treatments). This protocol is optimized for NIH 3T3 cells. </li>
 ...

<ol>
	<li>Parodi, A. J., Behrens, N. H., Leloir, L. F., Carminatti, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+role+of+polyprenol-bound+saccharides+as+intermediates+in+glycoprotein+synthesis+in+liver.">The role of polyprenol-bound saccharides as intermediates in glycoprotein synthesis in liver.</a> Proc Natl Acad Sci U S A. 69 (11), 3268-3272 (1972).</li><li>Avezov, E., Frenkel, Z., Ehrlich, M., Herscovics, A., Lederkremer, G. Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Endoplasmic+reticulum+(ER)+mannosidase+I+is+compartmentalized+and+required+for+N-glycan+trimming+to+Man5-6GlcNAc2+in+glycoprotein+ER-associated+degradation.">Endoplasmic reticulum (ER) mannosidase I is compartmentalized and required for N-glycan trimming to Man5-6GlcNAc2 in glycoprotein ER-associated degradation.</a> Mol Biol Cell. 19 (1), 216-225 (2008).</li><li>Frenkel, Z., Gregory, W., Kornfeld, S., Lederkremer, G. Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Endoplasmic+reticulum-associated+degradation+of+mammalian+glycoproteins+involves+sugar+chain+trimming+to+Man6-5GlcNAc2.">Endoplasmic reticulum-associated degradation of mammalian glycoproteins involves sugar chain trimming to Man6-5GlcNAc2.</a> J Biol Chem. 278 (36), 34119-34124 (2003).</li><li>Hosokawa, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Enhancement+of+endoplasmic+reticulum+(ER)+degradation+of+misfolded+Null+Hong+Kong+alpha1-antitrypsin+by+human+ER+mannosidase+I.">Enhancement of endoplasmic reticulum (ER) degradation of misfolded Null Hong Kong alpha1-antitrypsin by human ER mannosidase I.</a> J Biol Chem. 278 (28), 26287-26294 (2003).</li><li>Jakob, C. A., Burda, P., Roth, J., Aebi, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Degradation+of+misfolded+endoplasmic+reticulum+glycoproteins+in+Saccharomyces+cerevisiae+is+determined+by+a+specific+oligosaccharide+structure.">Degradation of misfolded endoplasmic reticulum glycoproteins in Saccharomyces cerevisiae is determined by a specific oligosaccharide structure.</a> J Cell Biol. 142 (5), 1223-1233 (1998).</li><li>Tolchinsky, S., Yuk, M. H., Ayalon, M., Lodish, H. F., Lederkremer, G. Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Membrane-bound+versus+secreted+forms+of+human+asialoglycoprotein+receptor+subunits.+Role+of+a+juxtamembrane+pentapeptide.">Membrane-bound versus secreted forms of human asialoglycoprotein receptor subunits. Role of a juxtamembrane pentapeptide.</a> J Biol Chem. 271 (24), 14496-14503 (1996).</li></ol>

The pulse-chase analysis of glycans in live cells with HPLC separation provides a method for studying the dynamics of oligosaccharide structural alterations throughout the life of a glycoprotein. There is growing evidence that such alterations are involved in producing the signals for ER folding, quality control and trafficking systems 2-5. The method can be applied not only for a specific glycoprotein of interest but also for analyzing the dynamics of the structure of total glycoproteins, as illustrated in th...

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		<div>
		<table border="1">
		<thead>
		<tr>
		<th>Material Name</th>
		<th>Type</th>
		<th>Company</th>
		<th>Catalogue Number</th>
		<th>Comment</th>
		</tr>
		</thead>
		<tbody>
		
<tr>
<td>600E Multisolvent delivery System controller</td>
<td>&nbsp;</td>
<td>Waters</td>
<td>WAT062710</td>
<td>&nbsp;</td>
<tr>
<td>Acetonitrile LiChrosolv (gradient grade for liquid chromatography)</td>
<td>&nbsp;</td>
<td>Merck Bioscience</td>
<td>1.0003</td>
<td>&nbsp;</td>
<tr>
<td>Microcon Amicon Ultra 0.5 ml 30K or Centricon ultracel YM-30</td>
<td>&nbsp;</td>
<td>Millipore</td>
<td>UFC503024 or 4208</td>
<td>&nbsp;</td>
<tr>
<td>Concentrator 5301, incl. 48 x 1.5 / 2.0 ml fixed-angle rotor</td>
<td>&nbsp;</td>
<td>Eppendorf</td>
<td>5301 000.016</td>
<td>&nbsp;</td>
<tr>
<td>Dialyzed Foetal Calf Serum</td>
<td>&nbsp;</td>
<td>Biological Industries</td>
<td>04-011-1A</td>
<td>&nbsp;</td>
<tr>
<td>Dulbecco's Modi&#xFB01;ed Eagle's Medium</td>
<td>&nbsp;</td>
<td>Gibco Invitrogen Cell Culture</td>
<td>41965039</td>
<td>&nbsp;</td>
<tr>
<td>Dulbecco&#x2019;s Modi&#xFB01;ed Eagle's Medium - glucose free</td>
<td>&nbsp;</td>
<td>Sigma-Aldrich</td>
<td>D5030</td>
<td>&nbsp;</td>
<tr>
<td>Dulbecco's Phosphate Buffered Saline (PBS)</td>
<td>&nbsp;</td>
<td>Sigma-Aldrich</td>
<td>D1408</td>
<td>&nbsp;</td>
<tr>
<td>EDTA disodium salt (Titriplex Iii)</td>
<td>&nbsp;</td>
<td>Merck</td>
<td>1084180250</td>
<td>&nbsp;</td>
<tr>
<td>Endo Hf Kit (1,000,000 units/ml)</td>
<td>&nbsp;</td>
<td>New England Biolabs</td>
<td>p0703S</td>
<td>&nbsp;</td>
<tr>
<td>Foetal Calf Serum (FCS)</td>
<td>&nbsp;</td>
<td>Biological Industries</td>
<td>04-001-1A</td>
<td>&nbsp;</td>
<tr>
<td>Frac-100 fraction collector</td>
<td>&nbsp;</td>
<td>Amersham Biosciences</td>
<td>18-1000-77</td>
<td>&nbsp;</td>
<tr>
<td>LS 6500 Liquid Scintillation Counting systems</td>
<td>&nbsp;</td>
<td>Beckman Coulter</td>
<td>510720</td>
<td>&nbsp;</td>
<tr>
<td>Mannose, D-[2-3H(N)]- (Specific Activity: 15-30Ci/mmol)</td>
<td>&nbsp;</td>
<td>PerkinElmer Life Sciences</td>
<td>NET570A</td>
<td>&nbsp;</td>
<tr>
<td>N-carbobenzoxyl-leucinyl-leucinyl-leucinal (MG-132)</td>
<td>&nbsp;</td>
<td>Calbiochem</td>
<td>474790</td>
<td>&nbsp;</td>
<tr>
<td>N-glycosidase F (1000 units/ml)</td>
<td>&nbsp;</td>
<td>Roche</td>
<td>11365177</td>
<td>&nbsp;</td>
<tr>
<td>N-octylglucoside</td>
<td>&nbsp;</td>
<td>Sigma-Aldrich</td>
<td>O3757</td>
<td>&nbsp;</td>
<tr>
<td>NIH 3T3 cells</td>
<td>&nbsp;</td>
<td>American Type Culture Collection (ATCC)</td>
<td>CRL-1658</td>
<td>&nbsp;</td>
<tr>
<td>Opti-Flour</td>
<td>&nbsp;</td>
<td>PerkinElmer Life Sciences</td>
<td>6013199</td>
<td>&nbsp;</td>
<tr>
<td>Phosphoric acid solution ( 49-51%, for HPLC)</td>
<td>&nbsp;</td>
<td>Fluka</td>
<td>79607</td>
<td>&nbsp;</td>
<tr>
<td>Protease Inhibitor Cocktail</td>
<td>&nbsp;</td>
<td>Sigma-Aldrich</td>
<td>P2714</td>
<td>&nbsp;</td>
<tr>
<td>Protein A-Sepharose beads</td>
<td>&nbsp;</td>
<td>Repligen</td>
<td>IPA300</td>
<td>&nbsp;</td>
<tr>
<td>Rabbit polyclonal anti-H2 carboxy-terminal 6</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>Sodium deoxycholate</td>
<td>&nbsp;</td>
<td>Sigma-Aldrich</td>
<td>30970</td>
<td>&nbsp;</td>
<tr>
<td>Sodium dodecyl sulfate</td>
<td>&nbsp;</td>
<td>Bio-RAD</td>
<td>161-0301</td>
<td>&nbsp;</td>
<tr>
<td>Sodium phosphate</td>
<td>&nbsp;</td>
<td>Sigma-Aldrich</td>
<td>342483</td>
<td>&nbsp;</td>
<tr>
<td>Sodium pyruvate solution (100mM)</td>
<td>&nbsp;</td>
<td>Sigma-Aldrich</td>
<td>S8636</td>
<td>&nbsp;</td>
<tr>
<td>Spherisorb NH2 Column, 5 &mu;m, 4.6 x 250 mm</td>
<td>&nbsp;</td>
<td>Waters</td>
<td>PSS831115</td>
<td>&nbsp;</td>
<tr>
<td>Triton X-100</td>
<td>&nbsp;</td>
<td>BDH</td>
<td>306324N</td>
<td>&nbsp;</td>
<tr>
<td>Vibra-Cell ultrasonic processors VCX 750</td>
<td>&nbsp;</td>
<td>Sonics and Materials, Inc.</td>
<td>690-003</td>
<td>&nbsp;</td>
<tr>
<td>Buffer A: 1% Triton X-100, 0.5% w/v sodium deoxycholate, Protease inhibitor cocktail 2% v/v in PBS</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>Buffer B: 0.5% w/v SDS, Protease inhibitor cocktail 2% v/v in PBS</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>Buffer C: N-glycosidase F reaction buffer: 200mM Na3PO4, pH 8.0, 4mM EDTA, 1.5% N-octylglucoside</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>NIH 3T3 stably expressing H2a 6</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>Buffer D: 0.5% Triton X-100, 0.25% w/v sodium deoxycholate, 0.5% w/v SDS, Protease inhibitor cocktail 2% v/v in PBS</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>Buffer E: 0.5% w/v SDS, 1% v/v 2-Mercaptoethanol, Protease inhibitor cocktail 2% v/v in PBS </td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>2-mercaptoethanol</td>
<td>&nbsp;</td>
<td>Sigma-Aldrich</td>
<td>M3148</td>
<td>&nbsp;</td>		</tbody>
		</table>
		</div>

pulse-chase analysis of n-linked sugar chains from glycoproteins in mammalian cells

Attachment of the Glc3Man9GlcNAc2 precursor oligosaccharide to nascent polypeptides in the ER is a common modification for secretory proteins. Although this modification was implicated in several biological processes, additional aspects of its function are emerging, with recent evidence of its role in the production of signals for glycoprotein quality control and trafficking. Thus, phenomena related to N-linked glycans and their processing are being intensively investigated. Methods that have been recently developed for proteomic analysis have greatly improved the characterization of glycoprotein N-linked glycans. Nevertheless, they do not provide insight into the dynamics of the sugar chain processing involved. For this, labeling and pulse-chase analysis protocols are used that are usually complex and give very low yields. We describe here a simple method for the isolation and analysis of metabolically labeled N-linked oligosaccharides. The protocol is based on labeling of cells with [2-3H] mannose, denaturing lysis and enzymatic release of the oligosaccharides from either a specifically immunoprecipitated protein of interest or from the general glycoprotein pool by sequential treatments with endo H and N-glycosidase F, followed by molecular filtration (Amicon). In this method the isolated oligosaccharides serve as an input for HPLC analysis, which allows discrimination between various glycan structures according to the number of monosaccharide units comprising them, with a resolution of a single monosaccharide. Using this method we were able to study high mannose N-linked oligosaccharide profiles of total cell glycoproteins after pulse-chase in normal conditions and under proteasome inhibition. These profiles were compared to those obtained from an immunoprecipitated ER-associated degradation (ERAD) substrate. Our results suggest that most NIH 3T3 cellular glycoproteins are relatively stable and that most of their oligosaccharides are trimmed to Man9-8GlcNAc2. In contrast, unstable ERAD substrates are trimmed to Man6-5GlcNAc2 and glycoproteins bearing these species accumulate upon inhibition of proteasomal degradation.

Watch this Scientific Journal Video about Pulse-chase Analysis of N-linked Sugar Chains from Glycoproteins in Mammalian Cells at JoVE.com

Pulse-chase Analysis of N-linked Sugar Chains from Glycoproteins in Mammalian Cells

We describe a method for analysis of the alteration of N-linked glycans through the early life of glycoproteins after their biosynthesis in mammalian cells. This is achieved by pulse-chase analysis of metabolically labeled glycans, enzymatic release from glycoproteins and examination by HPLC.

Attachment of the Glc3Man9GlcNAc2 precursor oligosaccharide to nascent polypeptides in the ER is a common modification for secretory proteins. Although ...

pulse-chase-analysis-n-linked-sugar-chains-from-glycoproteins

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Biology

15.1K vues.  Tel Aviv University. Nous décrivons une méthode pour l'analyse de l'altération des N-glycanes par le début de la vie des glycoprotéines après leur biosynthèse dans les cellules de mammifères. Ceci est réalisé par pulse-chase analyse des glycanes métaboliquement étiquetés, libération enzymatique des glycoprotéines et l'examen par HPLC.