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S S Koide

Publications and source records attributed to S S Koide.

At least 145 records · Page 8Linked to original sources
PubMed1982

In vitro induction of germinal vesicle breakdown in Xenopus laevis oocytes by melittin.

The bee venom, melittin, is an amphipathic polypeptide comprising 26 amino acids with known sequence. It consists of a hydrophobic and a basic hydrophilic segment, possesses lipolytic activity, and stimulates Na+-K+ pump activity. At 1.5 microM melittin induces 98% germinal vesicle breakdown (GVBD) in stage VI (Dumont) oocytes and 96% in stage IV oocytes. Progesterone (30 microM) induced 100% GVBD in stage VI oocytes and none in stage IV oocytes. GVBD occurs earlier with melittin than with progesterone, i.e., 3 h compared to 5 h. An unusual morphologic change observed with melittin is the occurrence of mottling of the animal pole. The inner boundary of the melanin layer appears irregular with projections extending into the cytoplasm. When stage VI oocytes were microinjected with 60 nl of 3 mM melittin only 48% showed GVBD indicating that the effectiveness of melittin was dependent upon the route of administration. On the other hand, 60% of stage VI oocytes underwent GVBD when microinjected with the cytosol fraction obtained from melittin-treated oocytes. Dissolution of isolated germinal vesicles did not occur when they were incubated in modified Barth's medium containing 3 mM melittin. The present results suggest that melittin induces GVBD by promoting the production of maturation promoting factor.

Animals↗
PubMed1982

RNA synthesis and poly(adenosine diphosphoribosyl) synthetase activity in developing mouse testis.

RNA polymerase I and II and poly(ADP-ribosyl) synthetase activities were determined in isolated nuclei prepared from mouse testes at 1, 3, and 8 weeks after birth. RNA polymerase II and poly(ADP-ribosyl) synthetase activities increased with progression of spermatogenesis and age while RNA polymerase I activity decreased. The observed inverse relationship of RNA polymerase I and II parallels the shift in species of RNA, produced during spermatogenesis. Poly(ADP-ribosyl) synthetase activity increased with age, reaching a peak at 8 weeks. These enzymatic activities in aged mouse testis nuclei were equivalent to that of 8-week-old mice. Germ cells from the adult testis were separated by unit gravity velocity sedimentation. The enriched fractions containing pachytene and round spermatids possessed RNA polymerase and poly(ADP-ribosyl) synthetase activities. The present results suggest that transcriptional events during spermatogenesis may be modulated by changes in the activities of variants of RNA polymerase.

Animals↗
PubMed1981

Choriogonadotropin-like antigen in a strain of Streptococcus faecalis and a strain of Staphylococcus simulans: detection, identification, and characterization.

The presence of choriogonadotropin- and alpha-subunit-like materials in two species of bacteria identified as Staphylococcus simulans and Streptococcus faecalis have been demonstrated by the indirect fluorescein-labeled and the indirect peroxidase-labeled immunocytochemical techniques, utilizing antiserum for human choriogonadotropin, for its alpha and beta-subunits and the bera-subunit COOH-terminal peptide. The bacteria were originally isolated from the urine of two patients with advanced forms of cancer. Chromatography done on the water-soluble extract of acetone powder preparations of the bacterial cultures revealed the presence of a material similar to the complete trophoblastic hormone and to its beta-subunit in the culture media of S. simulans, and to the beta-subunit in the media of S. faecalis. No free alpha-subunit was detectable. Furthermore, the choriogonadotropin-like factor demonstrated biological activity in in vivo assay systems. From the present results, it can be concluded that some species of "cancer-associated" bacteria can synthesize a human trophoblastic hormone-like glycoprotein with physicochemical properties similar to those of the human trophoblastic hormone that is biologically active and that is either released complete or as one of its subunits in the culture media.

Chorionic Gonadotropin↗
PubMed1980

Does H-Y antigen induce the heterogametic ovary?

To determine whether phylogenetically conservative H-Y antigen plays any part in gonadal differentiation among the nonmammalian vertebrates, we studied expression and binding of H-Y in the frog, Xenopus laevis. Soluble H-Y obtained from mouse testis and soluble H-W from chicken ovary bound specifically to cells of the ZZ testis from normal Xenopus males. In addition, H-Y (H-W) appeared selectively in the ovaries of ZZ genetic males that had been induced to become functional females by exposure to estradiol. Our observations suggest that H-Y (H-W) antigen may be involved in differentiation of the ZW ovary, and also that synthesis of H-Y may be regulated by sex steroids in the primitive ZW/ZZ species.

Animals↗
PubMed1979

ADP ribosylation of rat liver nucleosomal core histones.

When nucleosomal core histones were isolated from rat liver nuclei incubated with [14C]NAD+ and fractionated into the individual components (H2A, H2B, H3, and H4), [14C]adenosine diphosphate ribose (ADP-Rib) was found to be associated with all of them. However, while about 15% of the H2B molecules were modified, less than 2% of the other fractions contained radioactive ADP-Rib. The nucleotide attached to H2B was identified as a single monomer of ADP-Rib. On subjectint H2B to electrophoresis in polyacrylamide gels containing 2.5 M urea and 0.9 N acetic acid, one single band of H2B with 5% less mobility than the unomdified control was obtained. The linkage between H2B and ADP-Rib was rapidly hydrolyzed with 0.1 N NaOH or with 1 M neutral hydroxylamine. Hydrolysis of ADP-ribosylated H2B with trypsin generated a single peptide linked to ADP-Rib, which corresponded to the sequence Pro-Glu-Pro-Ala-Lys. We were able to dansylate the NH2-terminal proline, which proved that the imino group of this amino acid was not substituted. These findings, together with the chemical properties of the linkage, which were typical of those of an ester-like bond, strongly suggest that the ADP-Rib residue was linked to the gamma-COOH group of the glutamic acid in position 2 of H2B.

Adenosine Diphosphate Sugars↗
PubMed1979

ADP ribosylation of rat liver lysine-rich histone in vitro.

Purified rat liver nuclei were incubated with [14C]-NAD+ and the various nuclear protein fractions were separated. Forty per cent of the total radioactivity incorporated was associated with the histone fraction. Of this, about 50% was extracted with H1, in 0.5 N perchloric acid. When crude H1 was purified and fractionated into five different subfractions by chromatography on Bio-Rex 70, it was found that all the H1 subfractions contained radioactivity. This radioactive material was identified as oligomers of adenosine diphosphate ribose (ADP-Rib) with an average chain length which corresponded to trimers. The extent of the modification was dependent on the concentration of NAD+. About 60% of the H1 molecules were modified with a concentration of 1 mM NAD+. The presence of these oligomers of ADP-Rib introduced a large degree of microheterogeneity to H1 as detected by electrophoresis in polyacrylamide gels containing 2.5 M urea and 0.9 N acetic acid. Bands of H1 with 10 to 20% less mobility than the unmodified H1 were present. Also, as a consequence of large content of ADP-Rib, the absorption maximum shifted from 275 to 259 nm. The half-life of the bond between the oligomers of ADP-Rib and H1 was about 3 min at 37 degrees C in the presence of 0.1 N NaOH, and 10 m1 were modified. The site of ADP ribosylation in the NH2-terminal half was localized in the tryptic peptide extending from the NH2-terminal end to lysine 15. The site of modification of the COOH-erminal half was localized in the tryptic peptide which contained the only glutamic acid residue in this fragment of H1...

Adenosine Diphosphate Sugars↗
PubMed1979

Production of choriogonadotropin-like factor by a microorganism.

Extracts from an acetone powder preparation of a culture of a microorganism tentatively named Progenitor cryptocides contain choriogonadotropin (CG)-like factor as determined by radioimmunoassay with antiserum to human (h)CG beta subunit COOH-terminal peptide and radioreceptor assay with bovine corpus luteum membranes. Possible interference by proteases in the extracts was excluded. Immunoreactive materials reacting with antisera to hCG beta subunit and hCG beta subunit COOH-terminal peptide were also found in the extracts. No free alpha subunit was detected. The CG-like factor was purified by chromatography on Sephadex G-100, concanavalin A-Sepharose, and DEAE-Sephadex A-50. The factor was adsorbed by concanavalin A-Sepharose, suggesting that it contains mannose and glucose moieties. The factor was eluted at the same position as standard hCG on Sephadex G-100. It dissociated into two bands when subjected to sodium dodecyl sulfate/polyacrylamide gel electrophoresis; the bands corresponded to the respective standard hCG subunits. The biological activity of the purified factor as determined by the rat uterine weight assay and the ovarian weight assay was equivalent to 380 (95% confidence limits: 320-490) and 880 (780-1020) international units/mg, respectively. It can be concluded from the present results that a microorganism produces a glycoprotein that is biologically active and has physicochemical properties similar to those of hCG.

Bacteria↗
PubMed1977

Stimulation of poly(adenosine diphosphate ribose) synthase activity of Xenopus germinal vesicle by progesterone.

A practical procedure for the isolation of massive numbers of GV from oocytes of Xenopus laevis at various stages of oogenesis was developed. The method is simple, rapid, and easy to perform. The isolated GV possess high activity of poly(ADP-ribose) synthase. Incubation of class-A oocytes (stages V and VI) with progesterone resulted in a stimulation of the poly(ADP-ribose) synthase activity in the GV. The stimulation of enzymatic activity occurred prior to GVBD. This stimulatory effect of progesterone on enzymatic activity was blocked by cycloheximide and actinomycin D, suggesting that induction is dependent on protein and RNA synthesis. Progesterone, however, was unable to cause disintegration of GV or to stimulate poly(ADP-ribose) synthase activity of class-B oocytes (stages III and IV). This finding suggests that the oocytes must progress to a certain stage of differentiation before progesterone can induce GVBD or stimulate poly(ADP-ribose) synthase activity.

Animals↗