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Biomedical subjects

T Amano

Publications and source records attributed to T Amano.

At least 415 records · Page 23Linked to original sources
PubMed1976

Antigenic structures of Salmonella flagella. I. Presence of an antigenic determinant exposed at one end of flagellar fragments.

Salmonella flagellin, which is a constitutional subunit of the flagellum, was shown to have antigenic determinants distinct from its own serotypic ones. These antigenic determinants were found to be common to flagellins from the so-called g-complex serotypes, such as fg, mt, gm, gt, gp and gmptu, but not to those from other serotypes, such as a, i or enx. Rabbits immunized with flagellin of serotype "fg" produced anti-"fg" flagellin antibodies. Only about 20 percent of these corresponded to the serotype determinants of the "fg" on the surface of the flagella, and the remaining 80 percent reacted with the flagellin of the unrelated serotype "mt", and corresponded to the distinct determinants common to the flagellin molecules. These antigenic determinants were detected by the immunoferritin technique at only one, not both, terminals of the flagellar fragments, suggesting that a unidirectional arrangement of flagellin subunits in the flagella may expose the inherent conformation of the subunits at only one end of the flagellum.

Antibodies, Bacterial↗
PubMed1976

Immune bactericidal reactions by guinea-pig gamma1 and gamma2 antibodies.

Guinea-pigs produced both gamma1 and gamma2 antibodies against Escherichia coli K12, W3110/SM when they were injected intraperitoneally with a suspension of heat-killed bacteria without adjuvant twice a week for 12 weeks. The antibodies were separated by DEAE-cellulose chromatography. The gamma1 antibodies gave PCA reaction against soluble antigens prepared from sonicated E. coli, but the gamma2 antibodies did not. Both gamma1 and gamma2 antibodies induced complement-mediated bactericidal reaction against the homologous bacteria. In the case of gamma1 antibodies presensitization of bacteria with the antibodies before the addition of complement enhanced their bactericidal activity to a degree, EGTA inhibited the bactericidal activity of gamma2 antibodies, more than that of gamma1 antibodies. It is suggested that the gamma1 antibodies kill bacteria via the alternative pathway of complement activation, whilst the gamma2 antibodies exert their bactericidal activity mainly through the classical pathway.

Animals↗
PubMed1975

Further studies on the specificity of the N- and C-terminal antigenic determinant of hen egg-white lysozyme.

The specificity of the N- and C-terminal antigenic determinant (P17: sequence Lys1-Cys6-Asn27, Trp123-Cys127-Leu129) of hen egg-white lysozyme (HL) was studied in more detail. In a Scatchard plot of the binding of 14C-acetyl HL with guinea pig purified anti-P17 antibody experimental values bent sharply near r=1. This suggests the presence of two antibody populations with different affinities for HL or possible steric hindrance in the binding of a second HL molecule to the second binding site of the antibody molecule. The antigenic activities of various peptides were tested by measuring their inhibition of the binding of 14C-acetyl-P17 with the anti-P17 antibody. Only P17 and P17t (sequence Lys1-Cys6-Homoser12, Trp123-Cys127-Leu129) were inhibitory, with KI values of 2.0 times 10(4) and 8.1 times 10(3), respectively. These results indicate that the direct binding site of P17 to anti-P17 antibody may be located in the terminal portion of P17 (sequence Lys1-Cys6-Homoser12, Trp123-Cys127-Leu129) while the rest of P17 may be important in maintaining the conformation of this determinant. The single disulphide blood involved in this determinant is essential for manifestation of immunological activity.

Animals↗
PubMed1975

Comparative studies on antibody formation against hen egg white lysozyme and its split fragment.

A peptide fragment Fr. 17 (Lys1-Cys-Asn27 Leu129-Cys-Ala122) of hen egg white lysozyme (HL) was previously found to retain at least one antigenic determinant region of the native protein. In this work a highly purified preparation of Fr. 17, contaminated with less than 0.01% HL and less than 1% of other fragments was found to be strongly immunogenic to rabbits. The kinetic patterns of antibody formation against Fr.17, assayed by passive hemagglutination (PHA), were quite different from those of antibody formation against HL. The specificity of the antibody elicited to Fr. 17 was mainly directed to the Fr. 9-10-a region (Ala11-Asn27) while that of the antibody elicited to the Fr. 17 region in native HL was directed to the Fr. 15-b region (Lys1-Cys-Ala10 Leu129-Cys-Trp123). It is concluded that in the process of antibody formation, the recognition of the Fr. 17 region in native HL is different from that of fragment Fr. 17.

Animals↗