Succinylchymotrypsin

Succinylchymotrypsin was prepared from succinylchymotrypsinogen with trypsin and purified by DEAE-Sephadex chromatography.

The total 15 lysyl and N-terminal amino residues of chymotrypsinogen were succinylated. About 23.5 out of 49 seryl and threonyl residues and none in the total 4 tyrosyl residues in succinylchymotrypsin were modified

The helix content of succinylchymotrypsin was about 8.4%.

The pK_app of N-terminal amino group in succinylchymotrypsin did not change and that of tyrosyl residues shifted to alkali side, in comparison with those of unmodified α-chymotrypsin.

The k_cat of succinylchymotrypsin increased and its Km did not change within experimental error, in comparison with those of α-chymotrypsin.     

Taxonomy of Producing Organism,and Production,Isolation, Physico-chemical Properties and Biological Activities of Cirratiomycin A and B

The new peptide antibiotics have been obtained from the culture filtrate of a streptomycete, strain 248-Sq2, isolated from a soil sample collected at Nagano Prefecture, Japan.

On the basis of taxonomic studies, the producing organisms is designated as Streptomyces cirratus. Two active principles are named cirratiomycin A and B.

These antibiotics exhibit a narrow range of activities against Lactobacillus casei and some strains of Streptococcus and Mycobacterium.     

Effects of starvation on the ultrastructure of the mouse parathyroid gland

Ultrastructural changes of the parathyroid glands of starved mice were examined. The parathyroid glands of the starved mice showed a decrease in the volume of Golgi complexes and storage granules and an increase in the volume of lipid droplets, and contained more heterogeneously dense bodies and multivesicular bodies compared with that of the control mice. In addition, the volume of mitochondria, cisternae of granular endoplasmic reticulum and secretory granules and the number of prosecretory granules appeared to be decreased compared to those of the control mice. Myelin-like structures were observed in the parathyroid glands of the starved mice. The results of our study provide support for the hypothesis that starvation exerts an inhibitory influence not only on the synthesis but also on release of parathyroid hormone.     

Induction of histidine decarboxylase activity in the spleen of mice treated with staphylococcal enterotoxin A and demonstration of its non-mast cell origin

Histidine decarboxylase (HDC) activity increased 13-, 7-, and 2-fold in the spleen, lung and liver, respectively, but not in other tissues of C57BL/6 mice injected i.v. with 50 micrograms/kg of Staphylococcal enterotoxin A (SEA). But even in the spleen, increase in the histamine level was only 1.5 times that of untreated mice. In genetically mast cell-deficient WBB6F1 - W/Wv mice HDC activity in the spleen increased to the same extent as in wild type WBB6F1 - +/+ mice on SEA treatment, but the histamine level in the spleen also increased 20-fold, whereas it increased only 1.4-fold in +/+ mice. These results suggest that the increases in HDC and histamine resulted from interaction of SEA with non-mast cells in tissues.     

Stability and localization of biotin-labeled murine monoclonal antibody to human gastric cancer in normal mice and nude mice-human tumor models

We examined the tissue localization of biotin-labeled murine monoclonal antibody (MAb) S202 directed against the human scirrhous gastric carcinoma cell line MK-01 in normal and tumor-bearing mice after intravenous (IV) administration. The biotin-labeled MAb proved to be stable in vivo under normal conditions, antibody titer being 1:256 at 4 hr after IV injection. At 24 hr after injection, the tumor was stained by the avidin-biotin-peroxidase complex (ABC) method. Biotin-labeled MAb was found to be suitable for detection of the xenografted tumor of nude mice. This study provides new information concerning the dynamics of the distribution of biotin-labeled MAb in vivo.     

Proliferative potential of murine peritoneal mast cells after degranulation induced by compound 48/80, substance P, tetradecanoylphorbol acetate, or calcium ionophore A23187.

Proliferative potential of degranulated mast cells was investigated. Mast cells were collected from the peritoneal cavity of mice, and degranulation was induced by compound 48/80, substance P, 12-O-tetradecanoylphorbol 13-acetate (TPA), or calcium ionophore A23187. The potentiality of colony formation in methylcellulose was not reduced by treatment of various concentrations of compound 48/80, substance P and TPA. When degranulation was induced by compound 48/80, substance P or TPA, proportion of highly degranulated mast cells containing less than five granules was rather small. In contrast, considerable proportion of highly degranulated mast cells was obtained after the treatment with the low concentration (0.1 microgram/ml) of A23187. These highly degranulated mast cells, which were individually picked up by the micromanipulator, proliferated not only in methylcellulose but also in the skin of mast cell-deficient WBB6F1-W/Wv mice. Inasmuch as we have already shown the proliferation of IgE-sensitized and Ag-stimulated mast cells, degranulated mast cells appear to retain the proliferative potential in general.     

Incidence of antibodies against human immunodeficiency virus, human T-cell lymphotropic virus type 1, hepatitis B virus, hemorrhagic fever with renal syndrome virus and Chlamydia in Tonga and western Samoa

Among the populations of Tonga and Western Samoa, serum antibodies against human immunodeficiency virus or hemorrhagic fever with renal syndrome virus were not detected (0/904 and 0/192). No serum samples were considered to be positive for antibody against human T-cell lymphotropic virus type 1 (0/527). Hepatitis B antigen and antibody were found in 4% (8/192) and 47% (90/192), respectively. Chlamydia trachomatis IgG and C. psittaci IgG antibodies were detected in 39% (75/192) and 47% (91/192), respectively. The possibilities of the spread of human immunodeficiency virus and hemorrhagic fever with renal syndrome virus on the islands when the viruses invade from abroad were discussed.     

Cloning and expression in Escherichia coli of cDNA for serine: pyruvate aminotransferase of rat liver

Cloned cDNAs for rat liver serine: pyruvate aminotransferase were obtained by screening of a cDNA expression bank of rat liver with an antibody against the enzyme. Nineteen clones were isolated from 33 000 transformants and most of them had common fragments of cDNA on analysis by digestion with some restriction enzymes. These clones were identified as those containing cDNA for serine:pyruvate aminotransferase by the following criteria. (a) At the nucleic acid level, a 500-base-pair fragment of cDNA prepared by digestion of cDNAs with EcoRI and PstI hybridized with the mRNA coding for serine:pyruvate aminotransferase as judged by hybrid-selected and hybrid-arrested translations. (b) Specific proteins were detected in nine bacterial clones, a 40-kDa protein in one clone and a 39-kDa protein in eight clones. Among them only the 40-kDa protein was found to be solubilized from the cell by sonication, and this protein was immunoprecipitated with an antibody against serine:pyruvate aminotransferase of rat liver. (c) High activity of serine:pyruvate aminotransferase was expressed both in whole cell suspension and sonicated extract prepared from the transformant producing the 40-kDa protein, and 99% of the activity was immunoreactive with the antibody. Two types of mRNA for serine:pyruvate aminotransferase were detected on the RNA blot analysis by using cloned cDNA fragment as a probe. The larger mRNA (approximately 1600 nucleotides) was glucagon-inducible while the smaller one (approximately 1500 nucleotides) was not affected by the hormone.