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Biomedical subjects

T Harada

Publications and source records attributed to T Harada.

At least 1,243 records · Page 69Linked to original sources
PubMed1975

Regulation of arylsulfatase synthesis by sulfur compounds in Klebsiella aerogenes.

In Klebsiella aerogenes, arylsulfatase synthesis was repressed by inorganic sulfate, sulfite, sulfide, thiosulfate, and cysteine, but not by methionine under normal growth conditions. We isolated cysteine-requiring mutants (Cys minus), and mutants (AtsS minus, AtsR minus) in which the regulation of arylsulfatase synthesis was altered. In the cysteine auxotroph, enzyme synthesis was also repressed by inorganic sulfate or cysteine. Kinetic studies on mutants of the cysteine auxotroph showed that inorganic sulfate repressed arylsulfatase synthesis and that this was not due to cysteine formed by reduction of sulfate. Arylsulfatase synthesis in the AtsS minus mutant was not repressed by inorganic sulfate but was repressed by cysteine. This mutant strain had a normal level of inorganic sulfate transport. Another mutant strain, defective in the inorganic sulfate transport system, synthesized arylsulfatase in the presence of inorganic sulfate but not in the presence of cysteine. The AtsS minus mutant could synthesize the enzyme in the presence of inorganic sulfate but not cysteine. The AtsR minus mutant could synthesize the enzyme in the presence of either inorganic sulfate or cysteine. These results suggest that there are two independent functional corepressors of arylsulfatase synthesis in K. aerogenes.

Biological Transport, Active↗
PubMed1975

Epidermal surface saccharides reactive with phytohemagglutinins and pemphigus antigen.

Inorder to study the relationship between epidermal surface saccharides and pemphigus antigen(s), fluorescein-labelled Concanavalin A (Con A) and Phytohemagglutinin-P (PHA-P) were used. These phytohemagglutinins were found to bind with the intercellular areas of human epidermis. Alpha-methyl-D-mannoside and alpha-methyl-D-glucoside inhibited the epidermal intercellular staining pattern produced by ConA-FITC, while N-acetyl-D-galactosamine blocked the same staining pattern produced by PHA-P-FITC. Normal human skin reacted with pemphigus antibody and pemphigus skin with the deposition of IgG both gave a positive intercellular staining pattern with fluorescein labelled phytohemagglutinins. Our data indicated the non-identity of the binding of Con A and PHA-P, and pemphigus antigen(s).

Aged↗
PubMed1975

Epidermal intercellular binding of concanavalin a and pemphigus antibody.

The binding sites of Concanavalin A (Con A) and pemphigus antibody in the intercellular spaces of the human epidermis have been investigated. Extraction of human skin with phosphate-buffered saline (PBS) and 70% ethanol resulted in complete loss of the binding sites of the pemphigus antibody, whereas the extracted skin still retained its reactivity to Con A. Preincubation with more than 0.25 mg/ml of Con A with normal skin caused a reduction in the binding of pemphigus sera. However, preincubation of pemphigus sera with human skin caused no inhibition of the subsequent binding of fluorescein-labelled Con A. These results indicate that Con A binding sites might be related to, but not identical with those of pemphigus antibody.

Antibodies↗
PubMed1975

Serologic differences in strains of Sporothrix schenckii.

To obtain evidence that Sporothrix scheneckii enters the body by contact with contaminated materials, the antigenic property of strains from different sources was investigated. The reciprocal absorption test of the antisera against a soil isolate and a human isolate (KO 4606) showed that the absorbed antisera against KO 4606 possessed unique antigen(s) in addition to the common antigen of both strains. Twenty-three clinical isolates were tested with absorbed antisera. Not all of them possessed the unique antigen(s), but there were serologic varieties among S. schenckii strains, regardless of their sources, clinical type of the disease and the morphology of the yeast phase cells.

Antigens, Fungal↗
PubMed1974

Formations of extracellular isoamylase and intracellular alpha-glucosidase and amylase(s) by Pseudomonas SB15 and a mutant strain.

Pseudomonas SB15, which produces extracellular isoamylase, was found to produce intracellular alpha-glucosidase and amylase(s) when grown on maltose. A mutant strain (MS1) derived from it, which formed isoamylase constitutively, also produced these intracellular enzymes constitutively. The activities of the enzymes produced in the mutant strain were much greater than those induced in the parent strain.

Amylases↗
PubMed1974

Active transport of alcohol in Corynebacterium acetophilum.

The transport of alcohols was studied in Corynebacterium acetophilum, which was isolated as a strain growing well on acetate and ethanol. The transport of ethanol was found to be inducible by ethanol, n-propanol, n-butanol, and acetate, whereas transport of methanol occurred by noninducible passive diffusion. The entry of ethanol into the cells occurred against a concentration gradient and showed saturation kinetics with two K(m) values of 2.4 x 10(-5) M and 6.0 x 10(-5) M. Uptake of ethanol was inhibited by sodium azide, sodium cyanide, 2,4-dinitrophenol, and p-chloromercuribenzoate. The transport of ethanol was competitively inhibited by normal alcohols, but not by iso- or tert-alcohols. From these studies, we concluded that an inducible active alcohol transport system mediates the entry of ethanol, n-propanol, or n-butanol into the cells of C. acetophilum.

1-Propanol↗
PubMed1974

Catabolite repression and derepression of arylsulfatase synthesis in Klebsiella aerogenes.

When a mutant (Mao(-)) of Klebsiella aerogenes lacking an enzyme for tyramine degradation (monoamine oxidase) was grown with d-xylose as a carbon source, arylsulfatase was repressed by inorganic sulfate and repression was relieved by tyramine. When the cells were grown on glucose, tyramine failed to derepress the arylsulfatase synthesis. When grown with methionine as the sole sulfur source, the enzyme was synthesized irrespective of the carbon source used. Addition of cyclic adenosine monophosphate overcame the catabolite repression of synthesis of the derepressed enzyme caused by tyramine. Uptake of tyramine was not affected by the carbon source. We isolated a mutant strain in which derepression of arylsulfatase synthesis by tyramine occurred even in the presence of glucose and inorganic sulfate. This strain also produced beta-galactosidase in the presence of an inducer and glucose. These results, and those on other mutant strains in which tyramine cannot derepress enzyme synthesis, strongly suggest that a protein factor regulated by catabolite repression is involved in the derepression of arylsulfatase synthesis by tyramine.

Culture Media↗