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Author Chacko, B. K. ♦ Appukuttan, P. S.
Source Sree Chitra Tirunal Institute for Medical Sciences & Technology
Content type Text
Publisher International Journal of Biological Macromolecules
File Format PDF
Language English
Subject Domain (in DDC) Natural sciences & mathematics ♦ Life sciences; biology ♦ Physiology & related subjects ♦ Biochemistry ♦ Technology ♦ Medicine & health
Subject Domain (in MeSH) Carbohydrates ♦ Amino Acids, Peptides, and Proteins ♦ Chemicals and Drugs ♦ Chemical Phenomena ♦ Biological Sciences
Subject Keyword Biochemistry
Abstract Peanut (Arachis hypogaea) agglutinin (PNA) is extensively used as tumour marker as it strongly recognises the cancer specific T antigen (Ga1 beta --> 3GalNAc-), but not its sialylated version. However, an additional specificity towards Gal beta1 --> 4GlcNAc (LacNAc), which is not tumour specific, had been attributed to PNA. For correct interpretation of lectin histochemical results we examined PNA sugar specificity using naturally occurring or semi-synthetic glycoproteins, matrix-immobilised galactosides and lectin-binding tissue glycoproteins, rather than mono- or disaccharides as ligands. Dot-blots, transfer blots or polystyrene plate coatings of the soluble glycoconjugates were probed with horse-radish peroxidase (HRP) conjugates of PNA and other lectins of known specificity. Modifications of PNA-binding glycoproteins, including selective removal of O-linked oligosaccharides and treatment with glycosidases revealed that Gal beta1 --> 4GlcNAc (LacNAc) was ineffective while terminal alpha -linked galactose (TAG) as well as exposed T antigen (Gal beta1 --> 3 GalNAc-) was excellent as sugar moiety in glycoproteins for their recognition by PNA. When immobilised, melibiose was superior to lactose in PNA binding. Results were confirmed using TAG-specific human serum anti-a-galactoside antibody. (C) 2001 Elsevier Science B.V. All rights reserved.
Education Level UG and PG
Learning Resource Type Article
Educational Framework Medical Council of India (MCI)
Volume Number 28
Issue Number 5
Page Count 7
Starting Page 365
Ending Page 371