The expression of reporter gene may be induced by activation of cryptic signalling sequences, as we found while constructing the mutS-lacZ fusion gene. We cloned the Escherichia coli lacZ gene encoding beta-galactosidase into a plasmid vector carrying the Thermus thermophilus mutS gene. The clones expected to produce beta-galactosidase as the C-terminal fusion were selected for the complementation of beta-galactosidase activity in a lacZ deficient E.
View Article and Find Full Text PDFBandeiraea (Griffonia) simplicifolia lectin-I, isolectin A(4)(GS I-A(4)), which is cytotoxic to the human colon cancer cell lines, is one of two lectin families derived from its seed extract. It contains only a homo-oligomer of subunit A, and is most specific for GalNAcalpha1-->. In order to elucidate the GS I-A(4)-glycoconjugate interactions in greater detail, the combining site of this lectin was further characterized by enzyme linked lectino-sorbent assay (ELLSA) and by inhibition of lectin-glycoprotein interactions.
View Article and Find Full Text PDFThe affinity of a lectin from the sponge Geodia cydonium (GCL-I) for multi-antennary Gal beta1-->4GlcNAc and Gal beta1-->3GalNAc ligands was studied by both the biotin/avidin-based microtiter plate lectin binding assay and the inhibition of lectin-glycoform interaction. Among the glycoforms tested for binding, GCL-I reacted strongly with three multi-antennary Gal beta1-->4GlcNAc clusters containing glycoproteins (asialo human and bovine alpha1-acid gps and asialo fetuin), T (Gal beta1-->3GalNAc) rich glycoprotein from porcine salivary gland, asialo bird nest gp, and human blood group A active cyst gp, while human and bovine alpha1-acid gps, fetuin, and Tn containing gps were inactive. Among the haptens tested for inhibition, tri-antennary Gal beta1-->4GlcNAc (Tri-II) was about 1500, 72, and 72 times more active than GalNAc, Gal beta1-->4GlcNAc (II), and Gal beta1-->3GalNAc (T), respectively.
View Article and Find Full Text PDFPrevious study on the binding properties of a lectin isolated from Codium fragile subspecies tomentosoides (CFT) indicates that this lectin recognizes the GalNAc alpha1--> sequence at both reducing and nonreducing ends. In this study, the carbohydrate specificity of CFT was further characterized by quantitative precipitin (QPA) and inhibition of lectin-enzyme binding assays. Of the glycoforms tested for QPA, all asialo-GalNAc alpha1--> containing glycoproteins reacted well with the lectin.
View Article and Find Full Text PDFSingle-cell PCR analyses of expressed Ig H and L chain sequences presented here show that certain rearrangements occur repeatedly and account for a major segment of the well-studied repertoire of B-1 cell autoantibodies that mediate the lysis of bromelain-treated mouse erythrocytes, i.e. antibodies reactive with phosphatldyicholine (PtC).
View Article and Find Full Text PDFBandeiraea (Griffonia) simplicifolia lectin-I, isolectin A4(GS I-A4) reacting with the Tn(GalNAc alpha1 --> Ser/Thr) sequence or human blood group Pk active disaccharide (E, Gal alpha1 --> 4Gal, galabiose) was studied by quantitative precipitin (QPA) and precipitin-inhibition assays. When human blood group P1 or Tn active glycoproteins were tested by QPA, GS I-A4 reacted strongly with both the Tn active glycoproteins purified from asialo porcine, ovine and armadillo submandibular glands and a P1 active glycoprotein isolated from sheep hydatid fluid. They precipitated over 80% of the lectin nitrogen added.
View Article and Find Full Text PDFBiochem Biophys Res Commun
November 1995
The affinity of Bandeiraea (Griffonia) simplicifolia lectin-I isolectin B4 (BSI-B4) for the isomer of human blood group B active disaccharide (B, Gal alpha 1-->3Gal), the Gal alpha 1-->4Gal galabiose ligand, was studied by quantitative precipitin (QPA) and precipitin-inhibition assays. When human blood group B, P1 and H active glycoproteins were tested by OPA. BSI-B4 reacted strongly with both the B active glycoprotein purified from human ovarian cyst fluid and a P1 active glycoprotein isolated from sheep hydatid fluid and precipitated over 86% of the lectin nitrogen added.
View Article and Find Full Text PDFA search for human monoclonal antibodies to protective antigens of bacteria revealed an immunoglobulin M lambda chain [IgM(lambda); designated IgMBEN] reactive with the Vi capsular polysaccharide of Salmonella typhi. Vi, a linear homopolymer of alpha(1-->4)GalApNAc that is O acetylated at C-3, is a licensed vaccine for typhoid fever. Immunologic properties of IgMBEN were compared to those of burro globulin prepared by intravenous injections of S.
View Article and Find Full Text PDFA human monoclonal antibody (HuA) specific for blood group A substance with two fucose groups was found to be immunochemically almost identical with that of a previously characterized mouse monoclonal anti-A, AC-1001. The VH and VL chain cDNAs of HuA were sequenced and compared with those of AC-1001. The human and mouse antibodies used VH and Vk genes that came from different families and shared minimal nucleotide and amino acid sequence identity.
View Article and Find Full Text PDFMethods Mol Biol
December 1995
Mouse antidextran monoclonal antibodies showed microheterogeneity which was analyzed by two-dimensional polyacrylamide gel electrophoresis (2-D PAGE). Not only the heavy (H) chains but also the light (L) chains were heterogeneous in terms of isoelectric point (pI). The higher the pI, the more prominent the H chain spots.
View Article and Find Full Text PDFThe adhesive energy in lectin-induced agglutination can be assessed by the deformation of erythrocytes in aggregates. Helix pomatia (HPA) and Dolichos biflorus (DBA) specifically agglutinated blood group A erythrocytes and induced a change in curvatures of cells at the end of the aggregates. The curvatures changed from concavity to convexity with increasing lectin concentrations.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
March 1994
Primary immunization of BALB/c mice with alpha(1-->6)dextran (DEX), a native bacterial polysaccharide, induces an unexpected pattern of splenic B-cell responses. After a peak of antibody-secreting B-cell response at day 4, deposition of dextran-anti-dextran immune complexes, as revealed by staining with both dextran and antibodies to dextran, occurs and persists in splenic follicles until at least the fourth week after immunization. Antigen-specific B cells appear and proliferate in such follicles, leading by day 11 to development of DEX-specific germinal centers as characterized by the presence of distinct regions of DEX+ peanut agglutinin-positive (PNA+) cells.
View Article and Find Full Text PDFThe shuffling of the V kappa-Ox1 light chain joined to J kappa 4 of J kappa 5 instead of J kappa 2 reduced or abolished antigen binding of three groove-type anti-(alpha 1-6)dextran monoclonal antibodies, raising questions as to the structural roles of J kappa in antibody combining sites. The J kappa 4 light chain used contains Pro95A at the V kappa-Ox1-J kappa 4 junction, as well as a Phe to Ile substitution at the beginning of this J kappa 4 segment. To predict whether the defect in antigen binding is a consequence of the J kappa replacement, the Pro insertion or the Phe to Ile substitution, model-building studies were performed.
View Article and Find Full Text PDFWe have characterized a human monoclonal IgM kappa, designated IgMDON, from a blood group B individual. IgMDON is specific for alpha-galactosyl residues on blood group B substance; its fine specificity as defined by hemagglutination, quantitative precipitin, and inhibition ELISA assays was for the defucosylated terminal Gal(alpha 1-3)Gal epitope. Gal(alpha 1-3)Gal epitopes are also found on a variety of normal and pathogenic intestinal bacteria, and polyclonal IgG antibodies with the same specificity are found in the serum of nearly all normal individuals.
View Article and Find Full Text PDFSequences of the third complementarity determining region of antibody heavy chains (CDRH3s) are listed according to their length. Human sequences vary from 2 to 26 amino acids residues, but less extensively in other species. When combined with the other five complementarity determining regions, this enormous length variation of CDRH3, together with amino acid substitutions in their sequences, can provide a very large number of antibody specificities and can influence the shape of antibody combining sites.
View Article and Find Full Text PDFThe authors have presented descriptions of posttraumatic changes, congenital defects, developmental, inflammatory and metabolic disorders included in the scripts of the Old Testament. Proficiency of ancient physicians is emphasised, they were greatly respected and regarded as a tool in Creator's hands.
View Article and Find Full Text PDFThe specificity of the anti A+N lectin of Moluccella laevis (MLL) was examined by hemagglutination experiments with enzyme-modified human erythrocytes and by inhibition of hemagglutination. In addition, binding to various glycoproteins and inhibition by different sugars and glycoproteins were examined by enzyme immunoassay with antibodies to the lectin. Treatment of AMM erythrocytes with proteolytic enzymes increased their agglutinability by MLL 4-16-fold; similar treatment of ONN cells decreased their agglutinability 8-16-fold.
View Article and Find Full Text PDFWe have previously noted that a specific amino acid sequence could form the second framework region of human, mouse and rabbit immunoglobulin light chains, suggesting that this sequence has been preserved for 80 million years. Through divergent evolution, each species has acquired a different set of framework region sequences; however, these sets still share a few similar or identical amino acid sequences. In the present study, we have identified such sequences for all four framework regions between human and mouse immunoglobulin light and heavy chains.
View Article and Find Full Text PDFThe variables regions of three syngeneic anti-idiotypic antibodies (Ab2s) were cloned and sequenced. They are encoded by different VL genes, two are from different members of V kappa-Ox1 superfamily. The H chains are encoded by VH genes belonging to three different VH families, J558, Q52 and 7183.
View Article and Find Full Text PDFT-cell receptor (Tcr) alpha chains are classified into four subgroups (I, II, III, and miscellaneous) based on the amino acid residues at positions 61 and 62. Subgroup I has Gly Phe at these positions, subgroup II has Arg Phe, subgroup III has Arg Leu, and subgroup miscellaneous has several other combinations. Variability plots for subgroups I, II, and III sequences show higher values around positions 93-103, 105, 108, 111, 113, and 115, suggesting that these positions may interact with the processed antigen molecules.
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