A cationic glycoprotein pattern in human serum and cerebrospinal fluid with pathological implications

Area of Science:

• Biochemistry
• Immunology
• Proteomics

Background:

• Highly glycosylated proteins with cationic isoelectric points (pH 6.5-9.5) were observed in patient biofluids.
• These glycoproteins are not previously described as regular serum proteins.
• The observed patterns were specific to individuals and absent in healthy controls.

Purpose of the Study:

• To characterize novel glycoproteins detected in serum and cerebrospinal fluid.
• To investigate the association of these glycoproteins with specific patient groups and conditions.
• To differentiate these glycoproteins from known serum proteins like immunoglobulins.

Main Methods:

• Isoelectric focusing was employed for protein separation.
• Immunoassay utilizing digoxigenylated carbohydrate moieties detected glycoconjugates.
• Lectin binding was used to infer the presence of sialic acid.

Main Results:

• Unique glycoprotein patterns were identified in 7% of patients (n=400), distinct from 100 healthy controls.
• These glycoproteins differed from immunoglobulin G, oligoclonal immunoglobulin G, paraproteins, and regular cationic serum proteins.
• A carbohydrate content of approximately 30% was estimated, with evidence of sialic acid.

Conclusions:

• A novel class of highly glycosylated proteins has been identified in patients with various disorders.
• The presence of these glycoproteins is strongly correlated with inflammatory processes (90% of affected patients).
• Further research is needed to elucidate the pathophysiological significance and biochemical basis of these unique glycoproteins.