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Biomedical subjects

T Takagi

Publications and source records attributed to T Takagi.

At least 973 records · Page 54Linked to original sources
PubMed1976

Fluorescent probes for antibody active sites. I. Production of antibodies specific to the N-methyl-2-anilinonaphthalene-6-sulfonyl group in rabbits and some fluorescent properties of the hapten bound to the antibodies.

1. Rabbits were immunized with N-methyl-2-anilinonaphthalene-6-sulfonyl (MANS) bovine serum albumin (MANS-BSA) prepared by the reaction of bovine serum albumin with N-methyl-2-anilinonaphthalene-6-sulfonyl chloride to obtain IgG fraction containing anti-MANS antibodies. 2. Both N-methyl-2-anilinonaphthalene-6-sulfonate (MANSate) and N-methyl-2-anilinonaphthalene-6-sulfonamide (MANSamide), which are virtually non-fluorescent in aqueous solution, became strongly fluorescent, with a blue shift of about 100 nm, when they were specifically bound to the antibodies against the hapten group contained in the IgG fractions. 3. IgG fractions were obtained from five immunized rabbits at intervals after the primary immunization. The fluorescence characteristics of the hepten were carefully examined with preparations of IgG fraction differing in source and time of bleeding. One of the rabbits showed a very interesting immune response. The rabbit produced two groups of anti-MANS antibodies which were significantly different in their effect on the fluorescence properties of the hapten group. One of the groups was exclusively produced at the early stage in the immune response. The other group appeared at the late stage. It is suggested that the two groups differ as regards the structure of the hepten combining sites. 4. The above findings indicate that the MANS group can be successfully used as a hapten with useful properties as a fluorescent probe.

Anilino Naphthalenesulfonates↗
PubMed1976

Near-UV circular dichroism of trypsin inhibitor of adzuki beans attributable to disulfide groups.

The trypsin inhibitor of adzuki (Phaseolus angularis) beans shows a CD spectrum with a negative extremum at 280 nm and a positive shoulder around 245 nm. Since the inhibitor lacks tryptophan and tyrosine, the observed CD spectrum can be attributed to the six disulfide groups in the molecule. The CD features completely disappeared on reduction of the disulfide groups, and converged into a single negative extremum at 270 nm when the groups were modified to form mixed disulfides with glutathione. These observations of the CD properties of the inhibitor strongly suggest the presence of disulfide groups constrained with respect to their dihedral angles.

Circular Dichroism↗
PubMed1976

A clottable protein (coagulogen) of horseshoe crab hemocytes. Structural change of its polypeptide chain during gel formation.

A clottable protein (coagulogen) isolated from a hemocyte lysate of the Japanese horseshoe crab (Tachypleus tridentatus) was incubated with an endotoxin-activated clotting enzyme(s) partially purified from the same lysate, and its structural change during gel formation was examined. The results indicated that the enzymatic formation of gel involved limited proteolysis of the Arg-Gly and Arg-Thr linkages located in the N-terminal portion of the coagulogen, liberating peptide C.

Amino Acids↗
PubMed1976

Regulatory protein of vascular smooth muscle.

Preparations of native tropomyosin from the muscles of bovine aorta and carotid artery resensitized myosin B from either tissue. Neither preparation had any effect on desensitized myosin B from skeletal muscle but native tropomyosin from skeletal muscle could resensitize desensitized myosin B from vascular smooth muscles.

Animals↗
PubMed1976

Pharmacological studies on a new 1-benzoyloxy-alkylaminocycloalkane derivative (YAU-17) with special reference to its mucosa anesthetic activity.

A new compound, dl-cis-1-benzoyloxy-2-dimethylamino-1,2,3,4-tetrahydronaphthalane (YAU-17) was found to produce sciatic nerve block, corneal and intradermal anesthesia in guinea-pigs, which markedly exceeded the effect of procaine and lidocaine. YAU-17, when given orally to mice, was much less toxic than any other drugs tested, though YAU-17 showed a considerably high acute toxicity by i.v. route. Oral administration of YAU-17 was effective in antagonizing the emetic response of dogs to intragastric phenylalanine isopropyl ester, but produced no distinct inhibition against vomiting elicited by oral copper sulfate. Furthermore, it possessed a spasmolytic activity which was comparable to that of papaverine, and showed an effect of suppressing the mucosal intrinsic reflex in the dog intestine. These pharmacological properties of YAU-17 were qualitatively similar to those of oxetacaine which was used as one of the reference compounds.

2-Naphthylamine↗
PubMed1975

Amino acid sequence studies on the alpha chain of human fibrinogen. Location of four plasmin attack points and a covalent cross-linking site.

The amino acid sequence of a 38-residue midsection piece of the alpha chain of human fibrinogen has been determined using a combination of plasmin-derived peptides and cyanogen bromide fragments. The segment contains several important features, including four early plasmin attack points, one of the two alpha-chain cross-linking acceptor sites, and a peptide homologous to one isolated from plasmin digests of bovine fibrinogen, and reported to have anticoagulant activity. The segment is sequentially adjacent to and overlapping with a large molecular weight (20000-25000) fragment released during plasminolysis. This latter material is very rich in glycine and serine and deficient in nonpolar amino acids. It also contains the other alpha-chain cross-linking acceptor site.

Amino Acid Sequence↗
PubMed1975

Amino acid sequence of the carboxy-terminal cyanogen bromide peptide of the human fibrinogen beta-chain: homology with the corresponding gamma-chain peptide and presence in fragment D.

The carboxy-terminal cyanogen bromide fragment of the human fibrinogen beta-chain has been isolated and its structure determined. It is a nonapeptide with the sequence Lys-Ile-Arg-Pro-Phe-Phe-Pro-Gln-Gln and is homologous with a portion of the carboxy-terminal cyanogen bromide fragment of the gamma-chain. The peptide has also been isolated in full yield from cyanogen bromide digests of the plasmin-derived fragment D, indicating that the carboxy-terminal region of the beta-chain is resistant to plasmin digestion. In contrast, a small portion of the corresponding gamma-chain carboxy-terminal region was missing in the same fragment D.

Amino Acid Sequence↗
PubMed1975

Amino acid sequence studies on plasmin-derived fragments of human fibrinogen: amino-terminal sequences of intermediate and terminal fragments.

The progressive changes in amino-terminal sequence brought about by the digestion of human fibrinogen by plasmin have been studied. In addition, the limit products (fragments D and E) have been isolated and characterized in the same way. These studies have confirmed the generally accepted scheme of fibrinogen being changed into a large molecular weight fragment X, which in turn is converted into an intermediate fragment Y and a limit fragment D, followed by the breakdown of fragment Y into an additional fragment D and another core fragment E. Our data allow the precise identification of several of the junctions being attacked, including one in a region of the gamma-chain whose sequence has not previously been reported. The cleavages are not singular in any case, however, and, as suggested by others, intermediate species exist which correspond to "early D," "late D," etc. In addition to localizing the exact bonds split by plasmin, we have been able to sequentially position the core fragments relative to each other, since the gamma-chain amino terminus of fragment D has been found to be contiguous to the known carboxy-terminal sequence of fragment E.

Amino Acid Sequence↗