Abstract: Objective To define the differences in N-glycosylation of disease-specific immune and inflammatory proteins between lung cancer and benign lung disease. Methods A group of disease-specific serum immunoin-flammation-related protein complexes (IIRPCs) were isolated from the sera of two patients with lung adenocarcinoma and chronic pneumonia, by native-polyacrylamide gel electrophoresis (native-PAGE). The intact glycopeptides were obtained by in-gel trypsin digestion and then enriched by graphite phase carbon nitride. The glycopeptides were identified by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) coupled with GPSeeker database software. Results Totally 89 glycopeptides from 12 proteins were identified, 21 of which only existed in benign lung disease and 38 only be found in lung cancer samples. Ten of the 63 unique glycoforms from the 89 glycopeptides only existed in benign lung disease and only 21 were found in lung cancer. Conclusions The specific differences in N-glycosylation of disease-specific immune and inflammatory proteins are found between benign lung disease and lung cancer. These findings indicate that N-glycosylation may function as potential biomarker applied in diagnosis and prognosis of chronic diseases as well as a novel sight to molecular mechanism of chronic diseases.

Key words: biomarker disease-specific protein, disease-specific glycopeptide, disease-specific glycoform, benign and malignant lung diseases