کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1213435 1494143 2011 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Negative-ion MALDI-MS2 for discrimination of α2,3- and α2,6-sialylation on glycopeptides labeled with a pyrene derivative
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آنالیزی یا شیمی تجزیه
پیش نمایش صفحه اول مقاله
Negative-ion MALDI-MS2 for discrimination of α2,3- and α2,6-sialylation on glycopeptides labeled with a pyrene derivative
چکیده انگلیسی

Here, we propose a novel method for the discrimination of α2,3- and α2,6-sialylation on glycopeptides. To stabilize the sialic acids, the carboxyl moiety on the sialic acid as well as the C-terminus and side chain of the peptide backbone were derivatized using 1-pyrenyldiazomethane (PDAM). The derivatization can be performed on the target plate for matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS), thereby avoiding complicated and time-consuming purification steps. After the on-plate PDAM derivatization, samples were subjected to negative-ion MALDI-MS using 3AQ-CHCA as a matrix. Deprotonated ions of the PDAM-derivatized form were detected as the predominant species without loss of sialic acid. The negative-ion collision-induced dissociation (CID) of PDAM-derivatized isomeric sialylglycopeptides, derived from hen egg yolk, showed characteristic spectral patterns. These data made it possible to discriminate α2,3- and α2,6-sialylation. In addition, sialyl isomers of a glycan with an asparagine could be discriminated based on their CID spectra. In brief, the negative-ion CID of PDAM-derivatized glycopeptides with α2,6-sialylation gave an abundant 0,2A-type product ion, while that with α2,3-sialylation furnished a series of 2,4A/Y-type product ions with loss of sialic acids. The unique fragmentation behavior appears to be derived from the difference of pyrene binding positions after ionization, depending on the type of sialylation. Thus, we show that on-plate PDAM derivatization followed by negative-ion MALDI-MS2 is a simple and robust method for the discrimination of α2,3- and α2,6-sialylation on glycopeptides.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Chromatography B - Volume 879, Issues 17–18, 15 May 2011, Pages 1419–1428
نویسندگان
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