Application of champedak mannose‐binding lectin in the glycoproteomic profiling of serum samples unmasks reduced expression of alpha‐2 macroglobulin and complement factor B in patients with nasopharyngeal carcinoma

Abstract

The use of lectin affinity chromatography prior to 2-DE separation forms an alternative method to unmask the expression of targeted glycoproteins of lower abundance in serum samples. Reduced expression of alpha-2 macroglobulin (AMG) and complement factor B (CFB) was detected in sera of patients with nasopharyngeal carcinoma (NPC) when pooled serum samples of the patients and those of healthy individuals were subjected to affinity isolation using immobilized champedak mannose-binding lectin and analyzed by 2-DE and densitometry. The AMG and CFB spots were not detected in the 2-DE protein profiles when the same pooled serum samples were subjected to albumin and IgG depletion and neither were they detected when the depleted samples were analyzed by western blotting and lectin detection. Together with other acute-phase response proteins that were previously reported to be altered in expression in NPC patients, AMG and CFB may serve as useful complementary biomarkers for NPC.

Identification of O-glycosylated Proteins That Are Aberrantly Excreted in the Urine of Patients with Early Stage Ovarian Cancer

“…The 2-DE gels were silver stained according to the method of Shevchenko et al [21]. In-gel digestion of protein plugs from 2-DE gels was carried out according to a previously described method [22]. On the other hand, on-membrane digestion was performed according to the method described by Mu et al [7].…”

Chemically Induced Breast Tumors in Rats Are Detectable in Early Stages by Contrast Enhanced Magnetic Resonance Imaging but Not by Changes in the Acute-Phase Reactants in Serum

“…2-DE and mass spectrometry using the 4800 Plus MALDI TOF/TOF analyzer (Applied Biosystems/MDS Sciex, Toronto, Canada) were performed as previously described [8,24]. Protein spots were identified using the MASCOT search engine (Matrix Science Ltd, London, U.K.; release version 2.1.0) against rattus entries in the Swiss-Prot database (Last update October 23, 2008, containing 261513 sequences).…”

Proteomic Analysis of Whole Human Saliva Detects Enhanced Expression of Interleukin-1 Receptor Antagonist, Thioredoxin and Lipocalin-1 in Cigarette Smokers Compared to Non-Smokers

“…The protein spots (1–2 mm diameter) were excised from silver-stained gels with pipette tips and kept hydrated in clean microfuge tubes containing Milli-Q water, prior to the in-gel digestion. Trypsin digestion and precise identification by mass spectrometry, using the MALDI-TOF/TOF instrument (Applied Biosystem 4800 Proteomic Analyzer), were performed as previously described [46]. …”