ISSN:
1052-9306
Keywords:
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Serum transferrin precipitated with anti-transferrin serum was unalysed by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOFMS). The transferrin-antibody complex in the immuno-precipitates was separated into transferrin and IgG in an acidic pH, which is the usual condition of loading on MALDI-TOFMS. Ions of IgG and other minor components were not superimposed on the transferrin ions. Transferrin isoforms with different carbohydrate contents could be identified by this simple method easier than by affinity chromatography requiring the time-consuming preparation of an insolubilized specific antibody. The transferrin isoform with a molecular weight of ∼ 2.2 kDa smaller than normal transferrin, which is contained in the serum from patients with carbohydrate-deficient glycoprotein (CDG) syndrome, was identified by this method. In addition to the M1+ ion detected using sinapinic acid as a matrix, the M2+ and M3+ ions of transferrin were clearly detected using α-cyano-4-hydroxycinnamic acid as matrix and the molecular weight heterogeneity was identified more clearly in multivalent ions than that in the M1+ ion. The MALDI-TOF analysis of immunoprecipitates may serve as a simple and sensitive method to identify the molecular weight heterogeneity of various biological materials.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/bms.1200230408
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