Korea Basic Science Institute

Yeong Hee Ahn

Jong Shin Yoo

Jin Young Kim

Kun Cho

Soohyun Kim

Eun Sun Ji

Jae Yong Lee

Park Min Shin

Kun 0Ho

The present invention relates to a method for diagnosing cancer using information on aberrant glycosylation of glycoproteins, which is related with cancer progression. More particularly, the present invention relates to a peptide marker for cancer diagnosis and a method for diagnosing cancer using the peptide marker, wherein glycoproteins aberrantly glycosylated due to cancer incidence and progression is isolated using lectin; and marker peptides generated by hydrolysis of the glycoproteins isolated by the lectin is selected and quantified.

Method for diagnosing cancer using lectin

The present invention relates to a method for diagnosing cancer using information on the aberrant glycosylation of a glycoprotein. More precisely, the present invention relates to a cancer diagnosis peptide marker, which is screened by: a step of separating, using a lectin, a glycoprotein which is aberrantly glycosylated in accordance with the occurrence of cancer; and a step of selecting a hydrolyzed peptide marker derived from the aberrantly glycosylated glycoprotein by observing the quantitative changes in the separated glycoprotein. The present invention also relates to a method for diagnosing cancer using the peptide marker as an agent.

Cancer diagnosis marker using the aberrant glycosylation of a protein

The present invention relates to a method for phosphorylation site-specific labeling of phosphoproteome with a site-specific tagging reagent and analyzing of the resulting labeled one, more especially, a method for in-situ tagging of phosphorylation sites of phosphoproteins retained in polymeric gel with a nucleophilic tagging reagent. It also relates a method for generating new proteolytic cleavable sites at formerly phosphorylation sites by a proper choice of a nucleophilic tagging reagent. It also relates to a method for phosphopeptides analysis and phosphorylation site identification by in-gel digestion of the previously in-gel tagged proteins and subsequent mass analysis of the resulting peptides. The invention provides in-gel chemical tagging method for phosphoaminoacid residue of phosphoproteins retained in polymeric gel matrix. Phosphoprotein can be immobilized into gel matrix by a variety of methods such as gel electrophoresis. The immobilized phosphoproteins are retained in gel matrix during tagging reaction to phosphorylated aminoacid residue of phosphoproteins, and the resulting tagged proteins are also retained in gel matrix till following purification steps like washing of the tagging reagents are accomplished. The tagged proteins is digested by protease, and the resulting digested peptides is released from gel into solution and applied for peptide mass analysis. 

In-gel tagging and in-gel digestion for phosphoproteins analysis and phosphorylation site identification

The present invention relates to the method for tagging of carbohydrates with active methylene compound. Particularly, it relates to the method for tagging of carbohydrates with active methylene compound comprising the step of preparing carbohydrate conjugate in which carbohydrate and methylene compound are combined by mixing carbohydrate mixture and methylene compound under aqueous polar aprotic solvent containing amine base catalyst. The tagging method of the present invention does not need many kinds of chemical reagent and the reactions can be taken even in the presence of certain amount of impurities. So, it can be used for the analysis of oligosaccharide present in the various kinds of samples.

Method for tagging of carbohydrates with active methylene compound

Disclosed is a method of analyzing mass of the phosphoproteins or phosphopeptides and of analyzing phosphorylated positions at a phosphoprotein or phosphopeptide, comprising the steps of: 1) dephosphorylating at least one Ser and/or Thr residue of the phosphoprotein or phosphopeptide; 2) tagging the dephosphorylated amino acid residues with a tag having a R-L-G moiety wherein R is a nucleophilic functional group that selectively bind with dephosphorylated amino acid residues, G is selected from the group consisting of guanidine moiety or protected guanidine moiety such as a mono-N-protected guanidino group, a di-N,N'-protected guanidino group and an N&#x2032;-protected guanidino group, and L is a linker linking the R and the G; and 3) subjecting the tagged proteins or peptides to mass spectrometry. The method is capable of precisely analyzing mass of phosphoproteins of trace amounts as well as positions of phosphoryated amino acids.

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Chungcheongbuk-do, South Korea

Yeong Hee Ahn