Search PubMed⌕ Search

Biomedical subjects

M Katagiri

Publications and source records attributed to M Katagiri.

At least 253 records · Page 14Linked to original sources
PubMed1975

Papain-solubilized Ag-B antigens. I. Isolated and characterization of two components composing Ag-B antigens.

Ag-B antigen molecules of about 59,000 daltons were partially purified from papain digests of liver cell membranes of Fischer and ACI rats. These preparations were radioiodinated and the labeled Ag-B antigen molecultes were isolated as specific immune complexes with alloantibodies directed to Ag-B1 or Ag-B4. These specifically purified Ag-B antigen molecules were found to give two fragments of 37,000 and 11,000 daltons on sodium sulfate-acrylamide gel electrophoresis. The two fragments (or very similar ones) were isolated from the radioiodinated partially purified Ag-B antigen preparations by acid dissociation and subsequent gel filtration. The 37,000-dalton fragment retained the same Ag-B alloantigenic specificity as the parental 59,000-dalton Ag-B antigen molecules, whereas the 11,000-dalton fragment did not carry any detectable Ag-B alloantigenic activity. In the reaction with rabbit antisera raised against rat cell membranes, each fragment was shown to be antigenically distinctive.

Animals↗
PubMed1975

Papin-solubilized Ag-B antigens. II. Characterization of small sized Ag-B molecules.

Papain solubilization of rat Ag-B histocompatibility antigens produces Ag-B molecules of about 59,000 daltons which have been shown to contain two fragments bound noncovalently: one fragment about 37,000 daltons carrying Ag-B allospecificity, and another about 11,000 daltons, an apparent rat homologue of human beta2-microglobulin. Beside the 59,000-dalton Ag-B molecules, papain digests of liver cell membranes of ACI strain rats were found to contain Ag-B molecules of about 25,000 and 35,000 daltons. These smaller Ag-B molecules carried Ag-B private specificity of the rat strain (i.e., Ag-B4), as did the 59,000-dalton Ag-B molecules, and accounted for 40% of the solubilized Ag-B alloantigenic activity. The smaller Ag-B molecules were tested for the antigenic specificities that are characteristic of each of the two fragments of the 59,000-dalton molecules and detected by rabbit antiserum against rat cell membranes. The 35,000-dalton Ag-B molecules were found to contain the Ag-B 11,000-dalton fragment (i.e., rat beta2-microglobulin homologue) and to differ from the 59,000-dalton Ag-B molecules only in absence of a part of the 37,000-dalton fragment portion. The 25,000-dalton Ag-B molecules did not contain the rat beta2-microglobulin homologue and contained only a single component that is similar to the alloantigenic fragment portion of the 35,000-dalton Ag-B molecules. Similar 25,000-dalton Ag-B molecules (carrying Ag-B1 private specificity) of a single component were found in Fischer rat material. They accounted for 10% of the solubilized Ag-B alloantigenic activity.

Animals↗
PubMed1974

Relationship between the structures of fatty acid amide derivatives and their antimicrobial activities.

The structure-activity relationships of derivatives of the antibiotic cerulenin were investigated by chemically modifying dodecanoic acid, its skeletal back-bone. The dimethylamide derivatives were active against both gram-positive and -negative bacteria, and fungi. Among the compounds having modified groups at positions C2 and C4, the most active were those with a carbonyl group at C4 and a double bond at C2. The dimethylamide and pyrrolidine amide derivatives of this structure type were the most active. Activity against bacteria and yeast increased with the number of carbon atoms in the skeleton, with the maximum activity being observed at C=12. No significant differences in activity against fungi were observed with change in chain length.

Amides↗