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F Kametani

Publications and source records attributed to F Kametani.

68 records · Page 4Linked to original sources
PubMed1983

Reverse permeation of salicylate ion through cellulose membrane.

The reverse permeation of salicylate ion and the effect of bovine serum albumin on the permeation were studied in a sodium salicylate-sodium oxalate-water system. In passive transport the permeation flux of an ion is expressed by the linear combination of the two terms which represent the concentration and electric potential gradients. Because the mobility of the sodium ion is greater than the oxalate ion, salicylate ion moves against the concentration gradient, and follows the electric potential gradient in the initial stage of permeation. The reverse permeation of salicylate ion through a cellulose membrane was accelerated with a high concentration ratio of oxalate to salicylate ions and reached a maximum value after 10 hr in the absence of bovine serum albumin. After reaching a maximum value, the salicylate ion permeated along the concentration gradient. The maximum concentration efficiency was 11.2%. In the presence of bovine serum albumin, the reverse permeation of salicylate ion reached a maximum value after 3 hr.

Animals↗
PubMed1983

Comparative studies on the structure of the light chains of human immunoglobulins. IV. Assignment of a subsubgroup.

Amino acid sequence analysis was done on a human lambda Bence Jones protein NIG-64 with the major objective of determining the sequence of the variable region. Nineteen tryptic peptides covering 216 residues were isolated from the completely reduced and aminoethylated protein, and 17 of these were completely sequenced. These comprised the entire variable region and 11 from the constant region. For the remaining peptides covering the rest of the constant region, only partial sequences or the amino acid compositions were determined. All the tryptic peptides could be arranged in order on the basis of the above results and homology with other human lambda light chains of the same isotype. The sequence of the variable region of the protein is highly homologous with that of protein New of subgroup V lambda I as compared with other proteins of the same subgroup, suggesting that subgroup V lambda I may be further divided into subsubgroups, namely subsubgroups V lambda I-1 and V lambda I-2.

Amino Acid Sequence↗
PubMed1982

Uptake of hexavalent chromium by bovine erythrocytes and its interaction with cytoplasmic components; the role of glutathione.

Hexavalent chromium (Cr(VI)) anion gradually penetrated into bovine erythrocytes and bound with cytoplasmic components. Its penetration was strongly inhibited by the NH2-reactive agent, 4-acetamido-4'-isothiocyano-stilbene-2,2'-disulfonic acid (SITS) and the SH-reactive agent, N-ethylmaleimide (NEM). Gel filtration showed that the intracellular component that bound to chromium was hemoglobin. The binding affinity of Cr(VI) to hemoglobin in the absence of glutathione in vitro was found to be much less than in intact erythrocytes. However, in the presence of glutathione, the binding affinity of Cr(VI) to hemoglobin became much higher. This indicates that reduction of hemoglobin or Cr(VI) by glutathione is involved in the binding. Cr(VI) interacted only weakly with the membrane and did not cause hemolysis of bovine erythrocytes, unlike heavy metals such as Hg2+.

4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfo↗
PubMed1982

Transport of benzenesulfonic acid derivatives through the rat erythrocyte membrane.

Transport of benzenesulfonic acid derivatives through the rat erythrocyte membrane was studied. The transport properties, such as pH-dependence and effects of reagents reacting with amino-groups, were similar to those to anions like Cl- through the human erythrocyte membrane. The rate of transport of anions through rat erythrocyte membranes is higher than through those of other mammals, such as guinea pig and bovine erythrocyte membranes. This relatively high rate of transport makes the rat erythrocyte membrane suitable for use in comparative studies on the transport of slowly penetrating substances, such as organic anions. The transport velocities of benezenesulfonic acid derivatives were compared with their physico-chemical properties. It was shown that the hydrophobicity has no effect on the transport, but the electronic property has a significant effect: the transport rate is mainly dependent on the e- donor capacities. This feature is the inverse to the well-known inhibitory effect of these derivatives on other anion transport: the inhibition is mainly dependent on the e- acceptor capacities. It is suggested that the transport is regulated by the binding capacity of anions to the transport site.

Animals↗
PubMed1978

Structural requirements of alkyl acyldithiocarbazates for the uncoupling of oxidative phosphorylation in mitochondria.

A structure-activity relationship study on the uncoupling of alkyl acyldithiocarbazates was carried out. Greater activity was observed with increasing alkyl chain length, the optimum being C9. A further increase in alkyl chain length caused a decrease in the activity. Thione-thiol tautomeric forms with a dissociable proton were dound to be of primary importance for the uncoupling and the role of the acyl group was auxiliary. The reactivity of the SH group of alkyl acyldithiocarbazates with an SH-reagent was very low. These compounds facilitated the valinomycin-induced swelling of non-respiring mitochondria and non-sonicated lecithin liposomes in isotonic potassium acetate solution.

Animals↗
PubMed1978

Syntheses and uncoupling activities of alkyl dithiocarbazates and alkyl pyridinecarbonyldithiocarbazates.

A series of alkyl dithiocarbazates, alkyl 3-picolinoyldithiocarbazates, alkyl 3-nicotinoyldithiocarbazates, alkyl 3-isonicotinoyldithiocarbazates, and alkyl 3-picolinoyl-2-methyldithiocarbazates was prepared. These alkyl pyridinecarbonyldithiocarbazates were shown to be uncouplers of oxidative phosphorylation in mitochondria. The finding that uncoupling activity increased with increase in the length of the alkyl chains of the compounds indicates that hydrophobicity influences the activity. The nonyl derivatives had the highest activity. The results also suggested that a dissociable acidic proton is necessary for the uncoupling activity.

Animals↗
PubMedDate not supplied

Presenilin 1 cleavage is a universal event in human organs.

A panel of antibodies raised against various regions of human presenilin 1(PS1)--the amino-terminal domain, the domain between the transmembrane domains 1 and 2, the cleavage-site, loop domains, or carboxyl-terminal domain--was prepared to analyze PS1 in human tissues. We observed the predominance of two fragments (28-kDa NH2 and 18-kDa COOH fragments) in various tissues, including cerebral cortices. In addition to these two fragments, we found a previously unidentified amino-terminal fragment of PS1 with Mr 14 kDa in the lungs, spleen, pancreas, and testes. Using a sensitive ELISA for PS1, we measured the amount of PS1 species in tissues and found high contents of PS1 fragment in the testes. Our data show that common and unique processing pathways of PS1 occur in a tissue-dependent manner. It is likely that cleavage at the loop structure of PS1 to produce a functional form is a common event in human organs.

Alzheimer Disease↗
PubMedDate not supplied

The immunohistochemical demonstration of subsequences of the precursor of the amyloid A4 protein in senile plaques in Alzheimer's disease.

The actual presence of the predicted precursor of Alzheimer's disease amyloid A4 protein, reported by Kang et al. (1987) in the Alzheimer brain, has yet to be verified. To identify the various regions of this precursor, antibodies were raised against three synthetic polypeptides, R35 (residues 274-286), R36 (residues 527-540), and R37 (residues 681-695), subsequences of the precursor protein; the specificity of these antibodies was ascertained by ELISA. Upon immunohistochemical examination, the antibody to R35 failed to react, but the antibody to R36 (the extracellular part) stained the amyloid of senile plaques and the staining pattern was identical to that of anti-A4 antibody. The antibody to R37 (the C-terminal intracellular part) stained what may be degenerating neurites in senile plaques whereas the amyloid remained unstained. An anti-neurofilament (NF) antibody reacted with some of the R37-positive grains, but R37-negative grains also were seen. Further, some R37-positive grains were not stained by the anti-NF antibody. The anti-GFAP antibody and the anti-macrophage antibody did not stain the R37-positive grains. These findings indicate that the amyloid protein in senile plaques actually contains a larger polypeptide than the A4 protein, and suggest that the intracellular C-terminal part of the precursor may exist in the degenerated neurites seen in senile plaques.

Aged↗