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Updated: Mar 13, 2026
A Lectin HPLC Method to Enrich Selectively-glycosylated Peptides from Complex Biological Samples
Published on: October 1, 2009
The 88-kDa Eales' protein in serum is a complex of haptoglobin, complement C3, and galectin-1 as identified by liquid
Saravanan Ramanujam1,2, Bharathselvi Muthuvel1,3, Babu Aravind C4
1R. S. Mehta Jain Department of Biochemistry and Cell Biology, Vision Research Foundation, Sankara Nethralaya, Chennai, India.
Purpose:
Eales' disease (ED), an enigmatic inflammatory disease, affects peripheral retinal veins and thereby vision in males. This study was aimed at identifying and deciphering the role of a novel 88-kDa protein reported in the serum and vitreous of patients with ED.
Experimental Design:
The purified 88-kDa protein was identified by UPLC coupled ESI-QTOF-MS. The identified proteins were quantified in the serum from 20 ED patients and controls (age and sex matched), respectively by ELISA. The interaction of these proteins was studied using co-immunoprecipitation, western blot, and MS analyses. N-glycosylation of protein was observed by MS and lectin blot.
Results:
The 88-kDa protein was identified to be a complex of haptoglobin, complement C3, and galectin-1. ELISA results showed a 1.5-fold increase in levels of haptoglobin (p = 0.008), with level of complement C3 unaltered and 1.2-fold decreased serum galectin-1 levels (p = 0.003) in ED patients compared to controls. Co-immunoprecipitation illustrated the interaction between haptoglobin and complement C3. Reduced sialylation and increased β-1, 6-N-acetyl-glucosamine branched N-glycans were observed in haptoglobin of ED patients.
Conclusion:
The 88-kDa protein, a complex of haptoglobin, complement C3, and galectin-1, may play a potential role in ED pathogenesis while levels galectin-1 and haptoglobin may serve as potential biomarker of ED.
