The structures of glycophorin C N-glycans, a putative component of the GPC receptor site for Plasmodium falciparum EBA-140 ligand.

Glycophorins C and D are highly glycosylated integral sialoglycoproteins of human red blood cell membranes carrying the Gerbich blood group antigens. The O- and N-glycosidic chains of the major erythrocyte glycoprotein (Lisowska E. 2001, Antigenic properties of human glycophorins - an update.

A single point mutation in the gene encoding Gb3/CD77 synthase causes a rare inherited polyagglutination syndrome.

Rare polyagglutinable NOR erythrocytes contain three unique globoside (Gb4Cer) derivatives, NOR1, NOR(int), and NOR2, in which Gal(α1-4), GalNAc(β1-3)Gal(α1-4), and Gal(α1-4)GalNAc(β1-3)Gal(α1-4), respectively, are linked to the terminal GalNAc residue of Gb4Cer. NOR1 and NOR2, which both terminate with a Gal(α1-4)GalNAc- sequence, react with anti-NOR antibodies commonly present in human sera. While searching for an enzyme responsible for the biosynthesis of Gal(α1-4)GalNAc, we identified a mutation in the A4GALT gene encoding Gb3/CD77 synthase (α1,4-galactosyltransferase).

ABH blood group antigens in N-glycan of human glycophorin A.

We previously showed that a small proportion of the O-linked oligosaccharide chains of human glycophorin A (GPA) contains blood group A, B or H antigens, relevant to the ABO phenotype of the donor. The structures of these minor O-glycans have been established (Podbielska et al. (2004) [20]).

Analysis of recombinant Duffy protein-linked N-glycans using lectins and glycosidases.

Duffy antigen is a glycosylated blood group protein acting as a malarial and chemokine receptor. Using glycosylation mutants we have previously demonstrated, that all three potential glycosylation sites of the Duffy antigen are occupied by N-linked oligosaccharide chains. In this study, wild-type Duffy glycoprotein and three mutants, each containing a single N-glycan, were used to characterize the oligosaccharide chains by lectin blotting and endoglycosidase digestion.

Murine monoclonal anti-s and other anti-glycophorin B antibodies resulting from immunizations with a GPB.s peptide.

Background: The blood group antigens S and s are defined by amino acids Met or Thr at position 29, respectively, on glycophorin B (GPB). Commercial anti-s reagents are expensive to produce because of the scarcity of human anti-s serum. Our aim was to develop hybridoma cell lines that secrete reagent-grade anti-s monoclonal antibodies (MoAbs) to supplement the supply of human anti-s reagents.

Lectins as tools in glycoconjugate research.

Lectins are ubiquitous proteins of nonimmune origin, present in plants, microorganisms, animals and humans which specifically bind defined monosugars or oligosaccharide structures. Great progress has been made in recent years in understanding crucial roles played by lectins in many biological processes. Elucidation of carbohydrate specificity of human and animal lectins is of great importance for better understanding of these processes.

Structures of unique globoside elongation products present in erythrocytes with a rare NOR phenotype.

Rare polyagglutinable erythrocytes of NOR phenotype were found to contain two unique glycosphingolipids (designated NOR1 and NOR2). These components (not detected in normal erythrocytes) were reactive with Griffonia simplicifolia isolectin IB4 (GSL-IB4) and commonly present human anti-NOR antibodies. The NOR1 component has been reported to be a globoside containing a single galactose residue linked alpha1,4 to the terminal N-acetylgalactosamine.

Presence of natural anti-Galalpha1-4GalNAcbeta1-3Gal (anti-NOR) antibodies in animal sera.

Rare polyagglutinable NOR erythrocytes contain unusual globoside extention products terminating with a Galalpha1-4GalNAcbeta1-3Gal- unit. This trisaccharide epitope is recognized by recently characterized antibodies naturally occurring in most human sera (Duk et al., Glycobiology, 15, 109, 2005).

Galactosylation of IgG from rheumatoid arthritis (RA) patients--changes during therapy.

It is well documented that serum IgG from rheumatoid arthritis (RA) patients exhibits decreased galactosylation of its conservative N-glycans (Asn-297) in CH2 domains of the heavy chains; it has been shown that this agalactosylation is proportional to disease severity. In the present investigation we analyzed galactosylation of IgG derived from the patients using a modified ELISA-plate test, biosensor BIAcore and total sugar analysis (GC-MS). For ELISA and BIAcore the binding of IgG preparations, purified from the patients' sera, to two lectins: Ricinus communis (RCA-I) and Griffonia simplicifolia (GSL-II) was applied.

Anti-alpha-galactosyl antibodies recognizing epitopes terminating with alpha1,4-linked galactose: human natural and mouse monoclonal anti-NOR and anti-P1 antibodies.

The rare NOR erythrocytes, which are agglutinated by most human sera, contain unique glycosphingolipids (globoside elongation products) terminating with the sequence Galalpha1-4GalNAcbeta1-3Gal- recognized by common natural human antibodies. Anti-NOR antibodies were isolated from several human sera by affinity procedures, and their specificity was tested by inhibition of antibody binding to NOR-tri-polyacrylamide (PAA) conjugate (ELISA) by the synthetic oligosaccharides, Galalpha1-4GalNAcbeta1-3Gal (NOR-tri), Galalpha1-4GalNAc (NOR-di), Galalpha1-4Galbeta1-3Galbeta1-4Glc ((Gal)3Glc), and Galalpha1-4Gal (P1-di). Two major types of subspecificity of anti-NOR antibodies were found.

ABH blood group antigens in O-glycans of human glycophorin A.

The major O-linked oligosaccharide structures attached to human glycophorin A (GPA) have been extensively characterized previously. Our own recent findings, obtained by immunochemical methods, suggested the presence of blood group A and B determinants in O-glycans of human glycophorin originating from blood group A or B erythrocytes, respectively. Here, we elucidate the structure of O-glycans, isolated from GPA of blood group A, B, and O individuals by reductive beta-elimination, carrying A, B or H blood group epitopes, respectively.

The Fya, Fy6 and Fy3 epitopes of the Duffy blood group system recognized by new monoclonal antibodies: identification of a linear Fy3 epitope.

Four new anti-Duffy murine monoclonal antibodies (MAbs): two anti-Fy6 (MIMA-107 and MIMA-108), one anti-Fya (MIMA-19) and one anti-Fy3 (MIMA-29) were characterized. Identification of epitopes by means of synthetic peptides (Pepscan) showed that the anti-Fy6 reacted most strongly with peptides containing the sequence 19QLDFEDV25 of the Duffy glycoprotein, and less strongly with peptides containing LDFEDV (MIMA-107) or LDF only (MIMA-108). The anti-Fya recognized epitope 38DGDYGA43 containing the Gly42 residue, which defines the Fya blood group antigen.

Structure-function analysis of the extracellular domains of the Duffy antigen/receptor for chemokines: characterization of antibody and chemokine binding sites.

The Duffy antigen/receptor for chemokines (DARC), a seven-transmembrane glycoprotein carrying the Duffy (Fy) blood group, acts as a widely expressed promiscuous chemokine receptor. In a structure-function study, we analysed the binding of chemokines and anti-Fy monoclonal antibodies (mAbs) to K562 cells expressing 39 mutant forms of DARC with alanine substitutions spread out on the four extracellular domains (ECDs). Using synthetic peptides, we defined previously the Fy6 epitope (22-FEDVW-26), and we characterized the Fya epitope as the linear sequence 41-YGANLE-46.

Specificity of human anti-NOR antibodies, a distinct species of "natural" anti-alpha-galactosyl antibodies.

Natural anti-NOR antibodies are common in human sera and agglutinate human erythrocytes of a rare NOR phenotype. The NOR phenotype-related antigens are unique neutral glycosphingolipids recognized by these antibodies and Griffonia simplicifolia IB4 isolectin (GSL-IB4). The oligosaccharide chains of NOR glycolipids are terminated by Galalpha1-4GalNAcbeta1-3Galalpha units.

Adhesive properties of carcinoembryonic antigen glycoforms expressed in glycosylation-deficient Chinese hamster ovary cell lines.

Carcinoembryonic antigen (CEA) is an oncofoetal cell surface glycoprotein that serves as an important tumour marker for colorectal and some other carcinomas. Its immunoglobulin-like structure places CEA within the immunoglobulin superfamily. CEA functions in several biological roles including homotypic and heterotypic (with other CEA family members) cell adhesion.

Construction of dimeric F(ab) useful in blood group serology.

Background: When expressed in Escherichia coli, recombinant F(ab) contain a heavy-chain Fd fragment and a complete light-chain fragment. Because these F(ab) are monovalent, their avidity is significantly lower than that of a corresponding bivalent IgG antibody. In addition, when monovalent F(ab) are used in hemagglutination assays, antiglobulin reagents are required.