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Biomedical subjects

M Ota

Publications and source records attributed to M Ota.

At least 307 records · Page 17Linked to original sources
PubMed1987

Tissue specificities of protease A-like esteroprotease in male mice.

An esteroprotease hydrolyzing p-tosyl-L-arginine methyl ester (TAME) has been purified to homogeneity from male mice submandibular glands by the ammonium sulphate precipitation, Sephadex gel chromatography and DEAE-cellulose chromatography. The enzyme was shown as a single chain acidic protein (pI = 5.7) with the molecular weight of 27.5 K and evidence was obtained to reveal that it was similar to protease A. Using this enzyme as antigen we prepared anti-TAMEase antibody. The immunoblotting studies on tissue specificity using 20 different tissues from male mice revealed that cross-reactivities with anti-TAMEase antibody were observed in the crude extract from the sublingual gland, parotid gland and pancreas. The species specificity studies with the submandibular glands of 7 different species indicated that only the crude extract from rat submandibular glands reacted against anti-TAMEase antibody but it exerted a low TAMEase activity.

Amino Acid Sequence↗
PubMed1987

Subcellular distribution of glucocorticoid receptor in the neoplastic epithelial duct cell line from human salivary gland.

Neoplastic epithelial duct cell line from human salivary gland (HSG cell line) contains the specific glucocorticoid receptor. The time course study on the uptake of [3H]triamcinolone acetonide (TA), a synthetic glucocorticoid, by intact HSG cells in a growing monolayer culture showed that translocation of glucocorticoid receptors into nuclei occurred at 37 degrees C, but not at 0 degrees C. To elucidate the subcellular distribution of glucocorticoid receptor from HSG cells, a scaled-up-culture was employed. When the cells were incubated with [3H]TA at 0 degrees C, 94% of the receptors were found in the cytosol fraction, while only 6% of the receptors existed in the nuclei. When the cells were incubated at 37 degrees C, 49% of the receptor complexes were distributed in the nuclei and 74% of these nuclear receptor complexes were extractable with 5 mM pyridoxal phosphate.

Cell Fractionation↗
PubMed1987

Determination of ABO blood groups by radioimmunoassay using 125I-protein A.

Since the crystallizable fragment (Fc) portion of the immunoglobulin G (IgG) molecule is the binding site of Protein A, a radioimmunoassay procedure using 125I-Protein A was developed for identification of the ABO blood groups. The isotope level bound to Group A, B, or AB red cells decreased with the dilution of anti-A or -B, respectively. After sensitization by anti-A plus B in Group O serum, the isotope bindings were observed in Groups A, B, and AB cells, while no significant radioactive count appeared in Group O cells. Furthermore, there was little significant isotope binding in both Group A and B red cells sensitized by the serum from Group A or B blood containing mainly IgM anti-A or -B. A radioimmunoassay using 125I-Protein A is an excellent method for identifying ABO blood groups.

Blood Group Antigens↗
PubMed1986

Quantitative comparison of Rh1 (Rho, D) antigen on D, Du and d red cells by radioimmunoassay using 125I-protein A.

Relative Rh1 (Rho, D) antigen contents of the red Rh: 1 (Rh positive, D), Rh: wl (Rh variant, Du) and Rh: -1 (Rh negative, d) cells were estimated from the quantity of 125I-protein A bound to the sensitized red cells. The isotope binding activity to both D and Du cells decreased in parallel with the dilution of anti-D serum. The relative amount of the 125I-protein A bound to Du cells was about one-sixth that of D cells without papain treatment, while no isotope binding was observed in d cells. The Du red cells were quantitatively deficient in Rh1 (Rho, D) antigen activity compared with the D cells. A radioimmunoassay using 125I-protein A was a very useful method for studies regarding measuring the relative amounts of various blood group antigens.

Erythrocyte Membrane↗
PubMed1986

Transformation of androgen receptors from mouse submandibular glands by gel chromatography.

[3H]Methyltrienolone-bound and unbound androgen receptors from mouse submandibular glands bound to DNA-cellulose to a similar extent after gel chromatography. The receptors sedimented at 6 S in a low-salt gradient whereas if receptors were transformed with KCl (0.4 mol/l) they sedimented at 4 S. On DEAE-anion exchange chromatography both were eluted at a concentration of 0.07 mol KCl/l. These results suggest that two states of transformed androgen receptors exist. A 6 S transformed receptor may well derive by partial dissociation of an 8 S non-transformed receptor and this is caused by gel chromatography. Molybdate ions completely prevent both the transformation induced by gel chromatography and the secondary transformation during DEAE-anion exchange chromatography.

Animals↗
PubMed1986

Sex difference in the cytosolic and nuclear distribution of androgen receptor in mouse submandibular gland.

Cytosol and nuclear androgen receptors in submandibular glands of male and female mice were measured by an exchange assay at 0 degree C. The binding of [3H]methyltrienolone to cytosol receptors in females was mostly saturated within a short period of incubation (3 h), whereas the saturation was much slower in males; suggesting that almost all of the cytosol receptors were unoccupied in females and the receptors were partially occupied in males. Nuclear receptors were extracted with pyridoxal 5'-phosphate (5 mmol/l) from nuclear fractions with 93-95% efficiency. The exchange of the bound steroids occurred by 24-48 h at 0 degree C, suggesting that most of the nuclear androgen receptor was occupied. The binding was low at higher temperatures, probably due to inactivation of the receptor. Scatchard analysis showed that the apparent dissociation constants of cytosol and nuclear receptors were similar (0.8 and 0.9 nmol/l respectively) in both sexes. On the other hand, the number of androgen-binding sites in the nucleus was much higher in males than in females (1052 fmol/mg DNA and 32 fmol/mg DNA respectively), while the number in the cytosol was higher in females than in males (512 fmol/mg DNA and 368 fmol/mg DNA respectively). These observations show that androgen receptors exist mainly (74%) in the nuclei of males, while they exist mostly (94%) in the cytosol of females.

Animals↗
PubMed1986

Conversion of transformed androgen and glucocorticoid receptors to higher molecular forms.

The 4 S transformed androgen receptor from rat prostate and thymus converted to a higher molecular form (5-7 S) on low-salt conditions. The converted receptor retained the DNA-binding capacity as well as the 4 S transformed receptor. This conversion was also demonstrated on glucocorticoid receptor from rat liver and thymus. The sedimentation coefficients of both the converted receptors were affected by sodium molybdate, i.e., the receptors converted to a relatively smaller molecule in the presence of molybdate than in the absence of the reagent. These observations suggest that molybdate directly binds to the transformed receptors and prevents the excessive association of a factor(s) to the transformed receptors.

Animals↗
PubMed1986

Stabilization of androgen receptor by nonandrogenic steroids.

Binding of androgens including 5 alpha-dihydrotestosterone, testosterone and androstenedione stabilized the androgen receptor from rat submandibular gland with respect to its [3H]methyltrienolone binding activity. Nonandrogenic steroids, 0.5 microM of progesterone and estradiol-17 beta, or 5 microM of triamcinolone acetonide also satisfactorily stabilized the androgen receptor. These results suggest that the association of ligands, even if those ligands were not stereospecific for the androgen receptor, stabilizes the androgen receptor and prevents the loss of its binding capacity.

Androgens↗
PubMed1986

Characteristics of cytosol androgen receptor in rat thymus.

Male and female rat thymic cytosol contained specific androgen receptor. The apparent dissociation constants (Kd) were 2.4 nM in males and 2.5 nM in females, and the number of binding sites (NBS) were 23.7 fmol/mg protein in males and 34.2 fmol/mg protein in females. Transformation of receptor to the DNA binding state was achieved by heat or KCl treatment of [3H]R1881-receptor complex, and the characteristics of transformed and nontransformed receptors were investigated. The nontransformed androgen-receptor complex eluted at 0.20-0.25 M KCl from DEAE-Sephacel and sedimented at 9.1 S and its molecular weight was 255,000 on agarose gel chromatography, while the transformed receptor complex eluted at 0.03-0.15 M KCl with a broad peak and sedimented at 4.5 S and its molecular weight was 80,000-85,000. The minicolumn binding assay revealed that approximately 57% of the total receptor complexes bound to DNA-cellulose following heat treatment (20 degrees C, 1 h). Castration exerted no effect on the physicochemical properties of cytosol androgen receptor, but it increased the number of binding site to the female level.

Animals↗
PubMed1986

Cytosol glucocorticoid receptor in the neoplastic epithelial duct cell line from human salivary gland (HSG).

Neoplastic epithelial duct cell line from human salivary gland (HSG cell) contained cytosol glucocorticoid receptor. Scatchard analysis of cytosol indicated that the dissociation constant (Kd) was 5.6-6.5 nmol/l and the number of binding sites was 83-92 fmol/mg protein. A competitive assay showed that the binding sites for [3H]triamcinolone acetonide were specific to glucocorticoid. Glycerol density gradient centrifugation displayed that the [3H]triamcinolone acetonide receptor complexes sedimented in the 8.5 S region under low salt conditions and in the 4.2 S region under high salt condition (0.4 M KCl). The same high salt conditions induced an increased binding of [3H]triamcinolone acetonide complexes for DNA-cellulose.

Binding, Competitive↗
PubMed1985

Heterogeneity of molybdate-stabilized, nontransformed glucocorticoid receptor from rat liver.

Nontransformed glucocorticoid receptor stabilized with sodium molybdate exists as the heterogeneous forms which have slight differences in net charges and sedimentation coefficients. These differences could be detected by sequential analyses with DEAE-Sephacel chromatography and glycerol gradient centrifugation. The heterogeneity in the nontransformed receptor appears to be caused by the association of an acidic component(s) with the transformed receptor.

Animals↗