Search PubMedSearch

SEARCH · Search PubMed

Results for “Azirines”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources

Chemosensitivity of human bladder cancer cells in long-term culture and clinical responses to the selected anticancer drug.

In vitro sensitivity of an established cell line from human urinary bladder cancer to various chemotherapeutic agents was determined by 14C-leucine incorporation into the target cells. Of 12 drugs tested, Carboquone, Neocarzinostatin, Actinomycin D, Adriamycin, Mitomycin C and Chromomycin A3 produced intensive cytotoxic effects, while Thio-Tepa, Bleomycin, 5-Fluorouracil and Vincirstine were less cytotoxic, Intravesical instillation of Carboquone, one of the most toxic agents in vitro, resulted in complete or partial tumor remission in 6 of 9 patients with bladder cancer. Prophylactic effects of periodic intravesical Carboquone were also indicated in 7 of 8 patients who had experienced recurring superficial bladder tumors.

Antineoplastic Agents

The methionine-rich domain of the 54 kDa subunit of signal recognition particle is sufficient for the interaction with signal sequences.

The signal recognition particle (SRP) binds to signal sequences when they emerge from a translating ribosome and targets the complex of ribosome, nascent chain and SRP to the membrane of the rough endoplasmic reticulum (rER) allowing the co-translational translocation of the nascent chain. By photo-crosslinking it has been shown that the signal sequence of preprolactin (PPL) only interacts with the methionine-rich (M) domain of the 54 kDa protein subunit (SRP54) of SRP. Here we show that (i) a signal-anchor sequence is likewise crosslinked only to the methionine-rich domain of SRP54, (ii) free SRP54 can interact with signal sequences independently of the other components of SRP, (iii) its M domain suffices to perform this function, and (iv) an essentially intact M domain is required for signal sequence recognition. Alkylation of the N+G domain in intact SRP54 with N-ethyl maleimide (NEM), but not after cleavage with V8 protease, prevents the binding of a signal sequence to the M domain. This suggests a proximity between the N+G and M domains of SRP54 and raises the possibility that the role of the N+G domain may be to regulate the binding and/or the release of signal sequences.

Animals

Synthesis of oximes, aziridines, and allyl alcohols derived from substituted 1-phenyl-1-nonen-3-ones as potential cytotoxic and antitumor agents.

A number of nuclear-substituted 1-phenyl-1-nonen-3-one oximes were synthesized. Reduction of several of these compounds with lithium aluminum hydride yielded the corresponding 1-phenyl-2,3-epiminononanes, shown by 100-MHz NMR spectroscopy to be the cis-geometrical isomers. When several ring-substituted 4-dimethylaminomethyl-1-phenyl-1-nonen-3-ones were treated with hydroxylamine hydrochloride under forcing conditions, the product isolated was the corresponding oxime. Reaction under mild conditions led only to the isolation of the Michael addition product of the oxime in low yield. Reduction of some nuclear-substituted 4-dimethylaminomethyl-1-phenyl-1-nonen-3-ones with sodium borohydride led to the formation of the corresponding allyl alcohols, and the products were shown by 1H- and 13C-NMR spectroscopy to be the threo-isomers or, alternatively, a mixture of erythro- and threo-isomers. Reaction of phosphoric acid with one of the substituted allyl alcohols led to a diolefin, shown by NMR spectroscopy to be a mixture of (E, E)- and (E, Z)-isomers in a ratio of 65:35.

Allyl Compounds

Effects of alkylating agents on lymphocytes from controls and from patients with Fanconi's anemia. Studies of sister chromatid exchanges, chromosome aberrations, and kinetics of cell division.

The frequency of sister chromatid exchanges (SCE) and chromosome aberrations and the dynamics of cell division in peripheral blood lymphocytes of four patients with Fanconi's anemia were studied after in vitro exposure to alkylating agents TEPA and mitomycin. SCE frequency was significantly increased even after very low doses of mutagens, while chromosome aberrations were significantly increased only after high doses (0.160 micrograms/ml mitomycin and 10(-5) M TEPA). The responses of Fanconi's anemia cells and control cells did not differ significantly. The increased frequency of both SCE and chromosome aberrations was accompanied by gradual delay of cell division, which was most conspicuous in cells from patients with Fanconi's anemia.

Anemia, Aplastic

A unique hydrophobic domain of rat brain globular acetylcholinesterase for binding to cell membranes.

Both salt-soluble and detergent-soluble rat brain globular acetylcholinesterases (SS- and DS- AChE EC 3.1.1.7) are amphiphiles, as shown by detergent dependency of enzymatic activity and binding to liposomes. Proteinase K and papain treatment transformed SS-AChE and DS-AChE into forms that, in absence of detergent, no longer aggregated nor bound to liposomes. In contrast, phosphatidylinositol-specific phospholipase C had no effect on these properties. Labeling DS-AChE with 3-(trifluoromethyl)-3-(m-(125I)-iodophenyl) diazirine ([125I]TID) revealed, by polyacrylamide gel electrophoresis under reducing conditions, one single band of 69 kD apparent molecular mass. The same pattern was previously obtained with Bolton and Hunter reagent-labeled enzyme. Proteinase K treatment transformed the 11 S [125I]TID labeled AChE into a 4 S form which no longer showed 125I-radioactivity and was unable to bind to liposomes. These results are compatible with the existence of a hydrophobic segment present both on salt-soluble and detergent-soluble 11 S AChE as well as on the minor forms 4 S and 7 S. This segment is not linked to the catalytic subunits by disulfide bounds in contrast to the 20 kD non-catalytic subunit described by Inestrosa et al.

Acetylcholinesterase

Binary ethylenimine as an inactivant for foot-and-mouth disease virus and its application for vaccine production.

Foot-and-mouth disease virus was inactivated with binary ethylenimine formed apart from or directly in the virus suspension by the cyclization of 2-bromoethylamine hydrobromide or 2-chloroethylamine hydrochloride under alkaline conditions. The inactivation rates with binary ethylenimine prepared apart from the virus suspension in dilute sodium hydroxide with either 2-bromoethylamine hydrobromide or 2-chlorethylamine hydrochloride were higher than with pure ethylenimine. When binary ethylenime was prepared directly in the virus suspension only 2-bromoethylamine hydrobromide gave acceptable inactivation rates. The reduced inactivation rates for binary ethylenimine directly prepared in the virus suspension are due to the different cyclization rates of 2-bromoethylamine hydrobromide and 2-chloroethylamine hydrochloride and to the interference of bicarbonate in the cyclization reaction. The complement fixing antigen of foot-and-mouth disease virus was not affected by binary ethylenimine inactivation. Vaccines prepared with foot-and-mouth disease virus inactivated by binary ethylenimine were comparable in their immunogenicity to vaccines prepared with ethylenimine or N-acetylethylenimine used as inactivants. Application of binary ethylenimine in the preparation of foot-and-mouth disease vaccines considerably reduces the potential danger associated with handling pure ethylenimine and other aziridines.

Animals

The effect of acetylethyleneimine upon a strain of inactivated foot-and-mouth disease virus stored at 4 degrees C.

The presence of either thiosulphate-neutralized or free AEI was shown to degrade inactivated foot-and-mouth disease virus Type O (Hong Kong) antigen during storage at 4 degrees C. Deterioration was evident after 20 weeks of storage and little antigen remained at 36 weeks. Optimum stability was obtained by removing the residual inactivant immediately after inactivation.

Animals

Assessing hydrophobic regions of the plasma membrane H(+)-ATPase from Saccharomyces cerevisiae.

The hydrophobic, photoactivatable probe TID [3-trifluoromethyl-3-(m-[125I]iodophenyl)diazirine] was used to label the plasma membrane H(+)-ATPase from Saccharomyces cerevisiae. The H(+)-ATPase accounted for 43% of the total label associated with plasma membrane protein and incorporated 0.3 mol of [125I]TID per mol of 100 kDa polypeptide. The H(+)-ATPase was purified by octyl glucoside extraction and glycerol gradient centrifugation, and was cleaved by either cyanogen bromide digestion or limited tryptic proteolysis to isolate labeled fragments. Cyanogen bromide digestion resulted in numerous labeled fragments of mass less than 21 kDa. Seven fragments suitable for microsequence analysis were obtained by electrotransfer to poly(vinylidene difluoride) membranes. Five different regions of amino-acid sequence were identified, including fragments predicted to encompass both membrane-spanning and cytoplasmic protein structure domains. Most of the labeling of the cytoplasmic domain was concentrated in a region comprising amino acids 347 to 529. This catalytic region contains the site of phosphorylation and was previously suggested to be hydrophobic in character (Goffeau, A. and De Meis, L. (1990) J. Biol. 265, 15503-15505). Complementary labeling information was obtained from an analysis of limited tryptic fragments enriched for hydrophobic character. Six principal labeled fragments, of 29.6, 20.6, 16, 13.1, 11.4 and 9.7 kDa, were obtained. These fragments were found to comprise most of the putative transmembrane region and a portion of the cytoplasmic region that overlapped with the highly labeled active site-containing cyanogen bromide fragment. Overall, the extensive labeling of protein structure domains known to lie outside the bilayer suggests that [125I]TID labeling patterns cannot be unambiguously interpreted for the purpose of discerning membrane-embedded protein structure domains. It is proposed that caution should be applied in the interpretation of [125I]TID labeling patterns of the yeast plasma membrane H(+)-ATPase and that new and diverse approaches should be developed to provide a more definitive topology model.

Amino Acid Sequence

Bovine serum albumin as a catalyst. VI. Specificity of several nucleophilic groups in the protein for N-dansylaziridine.

The reaction of N-dansylaziridine with serum albumin (both bovine and human) results in incorporation of about 3 mol of covalently bound dansyl label per mol protein. This indicates that a number of nucleophilic groups in these proteins (in addition to the free sulfhydryl group) will react with this reagent. The reaction has been studied in detail for bovine serum albumin and the results suggest that one of the sites labelled by the reagent may be at the unusual "catalytic site" responsible for the enzyme-like activity of bovine serum albumin recently described (Taylor, R.P., Chau, V., Bryner, C. and Berga, S. (1975) J. Am. Chem. Soc. 97, 1934-1942). The reaction of N-dansylaziridine with a variety of other proteins indicates a pattern of labelling consistent with high specificity for the sulfhydryl group. The explanation for the unexpected excess reactivity of albumin with the "sulfhydryl specific" reagent N-dansylaziridine must be related to the three-dimensional structure in albumin which enables a number of specific residues to manifest unusually high degrees of nucleophilic reactivity.

Aziridines