This work was supported in part by the Natural Science Foundation of China (grant numbers 31471703, A0201300537 and 31671854 to J.V. and L.L., grant number 31470435 to G.Y.), and the 100 Foreign Talents Plan (grant number JSB2014012 to J.V.).

1. Sample collection
<ol>
	<li>Purchase different cultivars of fresh radish (Raphanus sativus L.).</li>
</ol>
2. Isolation of Protein from Radish
<ol>
	<li>Homogenize approximately 100 g of fresh radish with a kitchen blender for 10 min.</li>
	<li>Transfer the slurry to a 50 mL centrifuge tube and centrifuge at 14,000 &#215; g at 4 &#176;C for 20 min to remove the insoluble material.</li>
	<li>Transfer the supernatant carefully into a new 50 mL centrifuge tube and add an equa...

<ol>
	<li>Altmann, F. <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+Protein+Glycosylation+in+Allergy.">The Role of Protein Glycosylation in Allergy.</a> International Archives of Allergy and Immunology. 142 (2), 99-115 (2007).</li><li>Van Ree, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=&#946;+(1,+2)-xylose+and+&#945;+(1,+3)-fucose+residues+have+a+strong+contribution+in+IgE+binding+to+plant+glycoallergens.">&#946; (1, 2)-xylose and &#945; (1, 3)-fucose residues have a strong contribution in IgE binding to plant glycoallergens.</a> Journal of Biological Chemistry. 275 (15), 11451-11458 (2000).</li><li>Biswas, H., Chattopadhyaya, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stability+of+Curcuma+longa+rhizome+lectin:+Role+of+N-linked+glycosylation.">Stability of Curcuma longa rhizome lectin: Role of N-linked glycosylation.</a> Glycobiology. 26 (4), 410-426 (2016).</li><li>Lefebvre, B., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Role+of+N-glycosylation+sites+and+CXC+motifs+in+trafficking+of+Medicago+truncatula+Nod+factor+perception+protein+to+plasma+membrane.">Role of N-glycosylation sites and CXC motifs in trafficking of Medicago truncatula Nod factor perception protein to plasma membrane.</a> Journal of Biological Chemistry. 287 (14), 10812-10823 (2012).</li><li>Severino, V., et al. <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+the+glycan+moiety+on+the+structure-function+relationships+of+PD-L1,+type+1+ribosome-inactivating+protein+from+P.+dioica+leaves.">The role of the glycan moiety on the structure-function relationships of PD-L1, type 1 ribosome-inactivating protein from P. dioica leaves.</a> Molecular BioSystems. 6 (3), 570-579 (2010).</li><li>Lige, B., Ma, S., Van Huystee, R. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+effects+of+the+site-directed+removal+of+N-glycosylation+from+cationic+peanut+peroxidase+on+its+function.">The effects of the site-directed removal of N-glycosylation from cationic peanut peroxidase on its function.</a> Archives of Biochemistry and Biophysics. 386 (1), 17-24 (2001).</li><li>Ceriotti, A., Duranti, M., Bollini, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+N-glycosylation+on+the+folding+and+structure+of+plant+proteins.">Effects of N-glycosylation on the folding and structure of plant proteins.</a> Journal of Experimental Botany. 49 (324), 1091-1103 (1998).</li><li>Kamerling, J. P., Gerwig, G. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Strategies+for+the+Structural+Analysis+of+Carbohydrates.">Strategies for the Structural Analysis of Carbohydrates.</a> Comprehensive Glycoscience. , 1-68 (2007).</li><li>Huang, Y., Mechref, Y., Novotny, M. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microscale+nonreductive+release+of+O-linked+glycans+for+subsequent+analysis+through+MALDI+mass+spectrometry+and+capillary+electrophoresis.">Microscale nonreductive release of O-linked glycans for subsequent analysis through MALDI mass spectrometry and capillary electrophoresis.</a> Analytical Chemistry. 73 (24), 6063-6069 (2001).</li><li>Triguero, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chemical+and+enzymatic+N-glycan+release+comparison+for+N-glycan+profiling+of+monoclonal+antibodies+expressed+in+plants.">Chemical and enzymatic N-glycan release comparison for N-glycan profiling of monoclonal antibodies expressed in plants.</a> Analytical Biochemistry. 400 (2), 173-183 (2010).</li><li>Tretter, V., Altmann, F., Marz, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Peptide-N4-(N-acetyl-&#946;-glucosaminyl)asparagine+amidase+F+cannot+release+glycans+with+fucose+attached+&#945;1+&#8594;+3+to+the+asparagine-linked+N-acetylglucosamine+residue.">Peptide-N4-(N-acetyl-&#946;-glucosaminyl)asparagine amidase F cannot release glycans with fucose attached &#945;1 &#8594; 3 to the asparagine-linked N-acetylglucosamine residue.</a> European Journal of Biochemistry. 199 (3), 647-652 (1991).</li><li>Fan, J. -. Q., Lee, Y. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Detailed+studies+on+substrate+structure+requirements+of+glycoamidases+A+and+F.">Detailed studies on substrate structure requirements of glycoamidases A and F.</a> Journal of Biological Chemistry. 272 (43), 27058-27064 (1997).</li><li>Altmann, F., Paschinger, K., Dalik, T., Vorauer, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characterisation+of+peptide-N4-(N-acetyl-&#946;-glucosaminyl)asparagine+amidase+A+and+its+N-glycans.">Characterisation of peptide-N4-(N-acetyl-&#946;-glucosaminyl)asparagine amidase A and its N-glycans.</a> European Journal of Biochemistry. 252 (1), 118-123 (1998).</li><li>Altmann, F., Schweiszer, S., Weber, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Kinetic+comparison+of+peptide:+N-glycosidases+F+and+A+reveals+several+differences+in+substrate+specificity.">Kinetic comparison of peptide: N-glycosidases F and A reveals several differences in substrate specificity.</a> Glycoconjugate Journal. 12 (1), 84-93 (1995).</li><li>Wang, T., Voglmeir, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=PNGases+as+valuable+tools+in+glycoprotein+analysis.">PNGases as valuable tools in glycoprotein analysis.</a> Protein and Peptide Letters. 21 (10), 976-985 (2014).</li><li>Wang, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Discovery+and+characterization+of+a+novel+extremely+acidic+bacterial+N-glycanase+with+combined+advantages+of+PNGase+F+and+A.">Discovery and characterization of a novel extremely acidic bacterial N-glycanase with combined advantages of PNGase F and A.</a> Bioscience Reports. 34 (6), 00149 (2014).</li><li>Du, Y. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rapid+sample+preparation+methodology+for+plant+N-.glycan+analysis+using+acid-stable+PNGase+H+.">Rapid sample preparation methodology for plant N-.glycan analysis using acid-stable PNGase H+.</a> Journal of Agricultural and Food Chemistry. 63 (48), 10550-10555 (2015).</li><li>Wang, T., Hu, X. -. C., Cai, Z. -. P., Voglmeir, J., Liu, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Qualitative+and+Quantitative+Analysis+of+Carbohydrate+Modification+on+Glycoproteins+from+seeds+of+Ginkgo+biloba.">Qualitative and Quantitative Analysis of Carbohydrate Modification on Glycoproteins from seeds of Ginkgo biloba.</a> Journal of Agricultural and Food Chemistry. 65 (35), 7669-7679 (2017).</li><li>Ceroni, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=GlycoWorkbench:+a+tool+for+the+computer-assisted+annotation+of+mass+spectra+of+glycans.">GlycoWorkbench: a tool for the computer-assisted annotation of mass spectra of glycans.</a> Journal of Proteome Research. 7 (4), 1650-1659 (2008).</li></ol>

The protocol we have presented here allows the comparison of the N-glycan profiles of various cultivars of radish. A significant advantage of this method compared to existing protocols is that no buffer changes between the enzymatic release of N-glycans and the derivatization reaction with 2-AB are required. The most critical step of this procedure is the purification of N-glycans using the SPE column, as failure to remove salts or other impurities in the reaction mixture may negatively impact ...

N-glycans in plants have drawn increased attention in recent years, as previous research has highlighted N-glycans as a potential source of immunological cross-reactions that may provoke allergic responses1,2. It has been demonstrated previously that N-glycans on plant glycoproteins can affect catalytic activity3,4, thermostability and folding5,6 or subcellular localization and secretion7. In order to correlate the glycan structures with their respective functions, N-glycans must first be released from glycoproteins either chemically or enzymatically. The classical chemical method for releasing both N- and O-glycans is &#946;-elimination, in which alkaline sample treatment is accompanied by reduction with borohydride to yield an alditol8. However, this procedure precludes labeling with a fluorophore and causes significant decay of monosaccharide units from the reducing end of the glycan structure. Chemical deglycosylation based on ammonium hydroxide/carbonate treatment is also a commonly used alternative method9. Neither of these chemical release methods degrades intact proteins, which allows mass spectrometric analysis of unlabeled glycan pools without the interference of peptide fragments in the same mass range. However, one drawback of these methods is the increased degradation rate of &#945;1,3-fucosylated N-glycans, a common carbohydrate structure found in plants10. Alternatively, enzymatic release methods using peptide:N-glycanases (PNGases, EC 3.5.1.52) are also widely applied. Recombinant PNGase F (from Flavobacterium meningosepticum) is the most common choice and permits the release of all types of N-glycans, except the structures bearing a core &#945;1,3 fucose11,12. Therefore, PNGase A (isolated from almond seeds) is usually used for the analysis of plant N-glycans13. However, this enzyme deglycosylates only proteolytically-derived glycopeptides, and is unable to deglycosylate native glycoproteins14. Hence, a multi-step sample workup is required before further analysis, which causes extensive loss of glycans, especially those of low abundance15.The overall goal of the method is to present an optimized workflow for N-glycan release and fluorescence labeling in a simple and robust manner. The underlying rationale is that PNGase H+, which was recently discovered in Terriglobus roseus and can be recombinantly expressed in E. coli, can hydrolyze N-glycans directly from the protein scaffold in acidic conditions16. A key advantage of using PNGase H+ over alternative methods is that fluorescent labeling reactions can be performed in the same reaction tube without changing the reaction buffers17,18. The simple preparation conditions and high recovery of low-abundance oligosaccharides make this method a valuable tool in the analysis of N-glycans. This protocol is suitable for the analysis of N-glycans from various plant species.

<table border="0" cellpadding="0" cellspacing="0" style="width:880px;" width="880">
	<colgroup>
		<col />
		<col />
		<col />
		<col />
	</colgroup>
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:347px;">Chemicals:</td>
			<td style="width:123px;"></td>
			<td style="width:207px;"></td>
			<td style="width:204px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Trichloroacetic acid&#160;</td>
			<td>SCR, Shanghai</td>
			<td>80132618</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Acetic acid glacial</td>
			<td>Huada, Guangzhou</td>
			<td>64-19-7</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Acetonitrile</td>
			<td>General-reagent</td>
			<td>G80988C</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Trifluoroacetic acid</td>
			<td>Energy chemical</td>
			<td>W810031</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">2-aminobenzamide</td>
			<td>Heowns, Tianjin</td>
			<td>A41900</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Sodium cyanoborohydride</td>
			<td>J&#38;K Scientific Ltd</td>
			<td>314162</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Dimethyl sulfoxide</td>
			<td>Huada, Guangzhou</td>
			<td>67-68-5</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">2AB-labeled dextran ladder, 200 pmol</td>
			<td>Agilent Technologies</td>
			<td>AT-5190-6998</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">6-Aza-2-thiothymine&#160;</td>
			<td>Sigma</td>
			<td>275514</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Tools/Materials:</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Kitchen blender</td>
			<td>Bear, Guangzhou</td>
			<td>LLJ-A10T1</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Centrifuge</td>
			<td>Techcomp</td>
			<td>CT15RT</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Centrifugal Evaporator</td>
			<td>Hualida, Taicang</td>
			<td>LNG-T120</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">SPE column</td>
			<td>Supelco</td>
			<td>Supelclean ENVI Carb SPE column</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">MALDI-TOF mass spectrometer</td>
			<td>Bruker</td>
			<td>Autoflex</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">HPLC Analysis:</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">High-recovery HPLC vial</td>
			<td>Agilent Technologies</td>
			<td>&#160;# 5188-2788</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">HPLC System</td>
			<td>Shimadzu</td>
			<td>Nexera</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Fluorescence Detector for HPLC</td>
			<td>Shimadzu</td>
			<td>RF-20Axs&#160;</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Column oven</td>
			<td>Hengxin</td>
			<td>CO-2000</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">HPLC Column</td>
			<td>Waters</td>
			<td>Acquity UPLC BEH glycan column</td>
			<td>2.1 &#215; 150 mm, 1.7 &#956;m particle size</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">LCMS-grade Water</td>
			<td>Merck Millipore</td>
			<td>#WX00011</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">LCMS-grade Acetonitrile</td>
			<td>Merck Millipore</td>
			<td># 100029</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Formic acid</td>
			<td>Aladdin</td>
			<td>F112034</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Ammonia solution</td>
			<td>Aladdin</td>
			<td>A112080</td>
			<td></td>
		</tr>
	</tbody>
</table>

analysis of n-glycans from raphanus sativus cultivars using pngase h+

In recent years, the carbohydrate moieties of plants have received considerable attention, as they are a potential source of cross-reactive, allergy-provoking immune responses. In addition, carbohydrate structures also play a critical role in plant metabolism. Here, we present a simple and rapid method for preparing and analyzing N-glycans from different cultivars of radish (Raphanus sativus) using an N-glycanase specific for the release of plant-derived carbohydrate structures. To achieve this, crude trichloroacetic acid precipitates of radish homogenates were treated with PNGase H+, and labeled using 2-aminobenzamide as a fluorescent tag. The labeled N-glycan samples were subsequently analyzed by ultra performance liquid chromatography (UPLC) separation and matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry for a detailed structural evaluation and to quantify relative abundancies of the radish-derived N-glycan structures. This protocol can also be used for the analysis of N-glycans from various other plant species, and may be useful for further investigation of the function and effects of N-glycans on human health.

Figure 1 shows a schematic overview of the described protocol, including the isolation of (glyco-)proteins from radish, the preparation of N-glycans, the UPLC analysis, and the MALDI-TOF-MS analysis of these components. Figure 2 shows representative UPLC chromatograms of derivatized N-glycans of the analyzed radish cultivars. Figure 3 shows the obtained results of the 2AB-derivatize...

Watch this Scientific Journal Video about Analysis of N-glycans from Raphanus sativus Cultivars Using PNGase H+ at JoVE.com

Analysis of N-glycans from Raphanus sativus Cultivars Using PNGase H+

We describe a simple and rapid method for the preparation and analysis of N-glycans from different cultivars of radish (Raphanus sativus).

Analysis of N-glycans from Raphanus sativus Cultivars Using PNGase H+

In recent years, the carbohydrate moieties of plants have received considerable attention, as they are a potential source of cross-reactive, ...

This method can help answer questions in the field of plant Glycoscience such as how N-glycans of plant origin can be quickly analyzed and characterized. The main advantage of this technique is that it doesn't require any buffer changes between the enzymatic release of N-glycans and the derivatization reactions with 2-aminobenzamide. Demonstrating the procedure will be miss Ya-Min Du, and miss Shen-Li Zhen;two graduate students from the Glycomics and Glycan Bioengineering Research Center at Nanjing Agricultural University.To begin isolating the proteins, use a kitchen blender to homogenize approximately 100 grams of fresh radish for ten minutes. Transfer the resulting slurry to a 50 milliliter centrifuge tube. Centrifuge at 14, 000 times gravity at four degrees Celsius for 20 minutes to remove the insoluble material.After this, carefully transfer the supernatant into a new 50 milliliter centrifuge tube. Add an equal amount of a two molar trichloroacetic acid solution. Centrifuge at 14, 000 times gravity at four degrees Celsius for 30 minutes.And then remove the supernatant. Wash the pellet with 20 milliliters of deionized water. Centrifuge again at 14, 000 times gravity at four degrees Celsius for five minutes to remove soluble oligosaccharides and polysaccharides.Then, re-suspend the pellet with one milliliter of deionized water. And transfer the protein solution to a fresh 1.5 milliliter centrifuge tube. To begin preparing the N-glycans, mix 50 microliters of the protein solution with 0.2 milliunits of recombinant PNGase H+in ten millimolar acetic acid.Incubate at 37 degrees Celsius for 12 hours. Then, centrifuge at 14, 000 times gravity for five minutes to remove the extra protein and enzyme. Transfer the supernatant to a fresh 1.5 milliliter centrifuge tube until ready to purify the N-glycans.To begin purifying the N-glycans, wash the solid phase extraction column with three milliliters of water. Activate the column by adding three milliliters of an 80 percent acetonitrile solution containing trifluoroacetic acid. Then, three milliliters of deionized water to equilibrate the column.Transfer the sample onto the column and discard the flow through. Wash the column by adding 1.5 milliliters of deionized water. Failure to remove salts and add impurities in the sample mixture may negatively impact the efficiency of the fluorescence derivatization reaction.Then, add 1.5 milliliters of an aqueous 20 percent acetonitrile solution containing 0.1 percent TFA to elute the N-glycans into a two milliliter tube. Remove the solvent by centrifugal evaporation at room temperature, evaporating until the sample is completely dry. To begin fluorescence derivatization of N-glycans, prepare the 2-AB solution as outlined in the text protocol.Add five microliters of the prepared 2-AB solution to the dried samples. Vortex until each sample is completely dissolved. Incubate at 65 degrees Celsius for two hours.After this, let the sample cool to room temperature for five minutes. Add five microliters of deionized water and 40 microliters of acetonitrile to the cooled sample. Centrifuge at 14, 000 times gravity for three minutes.Then, transfer 48 microliters of the resulting supernatant into a 300 microliter high recovery HPLC vial. Store at negative 20 degrees Celsius for up to one month or when ready to use. To begin profiling, use a standard UPLC system equipped with a hydrophobic interaction liquid chromatography UPLC glycan column and connect it to an online fluorescence detector to analyze the samples.Set the excitation and emission wavelengths to 330 nanometers and 420 nanometers, respectively. Set the column temperature to 60 degrees Celsius. Next, inject 45 microliters of the sample into the UPLC system.Elute the N-glycans by UPLC using retention times of 15 and 40 minutes. Using two milliliters centrifuge tubes collect each observed UPLC peak fraction. Then, use centrifugal evaporation to dry the samples.Inject approximately one picomole of 2-AB labeled dextran standard to calibrate the plant N-glycan profiling and to assign their elution times and to standardize glucose units. To begin MALDI-TOF analysis, dissolve the dried samples in five microliters of LCMS grade water. Mix one microliter of this solution with one microliter of ATT solution.Then, pipet this mixture into the MALDI-TOF sample carrier. After this, use a MALDI-TOF mass spectrometer instrument to analyze the samples as outlined in the text protocol. In this study, N-glycan profiles are compared from various cultivars of radish.Representative UPLC chromatograms show that derivatized N-glycans and the relative abundance of each and different radishes can be successfully analyzed through this process. After this, MALDI-TOF mass spectroscopy is used to analyze the structures of 2-AB derivatized N-glycans. Though this method can provide insight into the composition of N-glycans from different Raphanus sativus cultivars, it can also be applied to other systems such as peanuts or other allergenic plant species.Once mastered, samples can be prepared within two working days which already includes the UPLC analysis procedure. When attempting this procedure, it's important to remember that the solid phase extraction columns used to isolate the N-glycans are sufficiently moistened with distilled water prior to sample application. Otherwise, binding of N-glycans to the column may be hampered.For additional verification of N-glycan structures, other methods can also be used. This could be, for example, sequential exoglycosidase treatments or MALDI-TOF MS N based fragmentation techniques. After its development, this technique paved the way for researchers in the field of Glycoscience to explore the composition and function of plant N-glycans more rapidly.After watching this video, you should have a good understanding of how to prepare N-glycans from different cultivars of radish using PNGase H+and how to analyze the 2-aminobenzamide derivatives by UPLC. Don't forget that working with trifluoroacetic acid and trichloroacetic acid can be extremely hazardous and precautions such as wearing protective gear should always be taken while performing this procedure.

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6.5K vistas.  Nanjing Agricultural University. This method can help answer questions in the field of plant Glycoscience such as how N-glycans of plant origin can be quickly analyzed and characterized. The main advantage of this technique is that it doesn't require any buffer changes between the enzymatic release of N-glycans and the derivatization reactions with 2-aminobenzamide. Demonstrating the procedure will be miss Ya-Min Du, and miss Shen-Li Zhen;two graduate students from the Glycomics and Glycan Bioengineering Research Center at N...