A new killer toxin produced by Saccharomyces cerevisiae

count. The new form belongs to the champions group of the genus, which also includes G . champions of western Panama, G. godmanl of Costa Rica end western Panama, as well as G. ruthvari . (Author's abatrad) Exra~tew, A. L., MARTIN, I. and Morrrovw, E. (Department of Microbiology, Faculty of Sciences, University of Granada, Granada, Spain) A new killer toxin produced by Saccharomyces rnrvisiae. Curt. Gant. S, 17 (1982) . A wtNE-INAICINa Saccharomyces cerrvistae yeast strain isolated in our laboratory produces two different killer toxins, each one encoded by one dsRNA plasmid. One toxin has the same spxificity as the one produced by strain M437 described by Naumov, but the dsRNA plasmid which encodes it migrates slightly faster in polyacrylamide gel electrophoresis . The othertoxin hes not been previously described, and is encodedby a dsRNA fraction which migrates at a lower rate than the x fraction of M437 . These two dsRNA plasmids canbe maintained separately in different yeast strains . (Authors' abstract) H. P. Kot.M EASTMAN, D. F., Dl~rw, G. P. and SsaAU ., H. J. (Department of Physiological Science, School of Veterinary Medicine, University of California, Davis, California, U.S .A .) Covalent binding of two pyrrolizidine alkaloids, senecionine and seneciphylline, to hepatic macromolecules and their distribution, excretion, and transfer into milk of lactating mice . Drug Metab. Dispos. 10, 236 (1982) . Two IrIACROCYCt.t c "C-pyrrolizidine alkaloids (PA's), senecionine and seneciphylline, were studied regarding the distribution, excretion, transfer into millr, and covalent binding to hepatic macromolecules in BALB/c mice. After i.p . injection, radioactivity was rapidly excreted in the urine and feces (84ß'o or greater) within 16 hr . The liver contained over 1.3~ of the dose at 16 hr. A small amount, 0.04ßm, of the dose was transferred into the milk in 16 hr ; the majority of radioactivity was found in the skim-milk fraction, suggesting that the PA's were transferred to the milk as water-soluble metabolites. Both PA's covalently bound to liver macromolecules (DNA, RNA, and protein). The binding to calf thymus DNA and microsomal macromolecules was measured In vitro . The binding was diminished in the absence of O, or a NADPH-generating system or by boiling the microsomea. No inhibition of the binding by KCN was observed. (Authors' abetted) H. P. Kot.xt STERZa., J., SwNTAVV, F., SenMeRA, P. and CttnLiN, J. (Institute of Microbiology, Czechoslovak Academy of Sciences, 142 20 Prague 4, and Institute of Medical Chemistry, Palackj~ University, 773 15 Olomouc, Czechoslovakia) Effect of oolchicine derivatives on the antibody response induced in vitro. Folly microbiol. Praha 27, 256 (1982). Et~ecr of 44 oolchicine derivatives on the induction of antibody response in tissue cultures was leafed. Lymphatic cells from the spleen of BALB/c mice were cultivated with antigen (sheep red blood cells) and the number of antibody forming cells was determined by the plaque tahnique . Most compounds with the immunoinhibitory effect are derived from the colchicine formula (I). The effect was increased by introducing ethyl, formyl or methylenedioxide groups . Colchinols exerted very good immunoinhtbitory effect resulting by contraction of tropolone ring C into the aromatic one. A complete loss of the effectivity was defected in the case of glucoside of colchicine, colchceine, iaocolchicine, oxyeolchicine, allocolchicine and in lumiderivatives of eolchicine . No correlations between the immunoinhibitory effect, toxicity and stathmokinetic effect were detected : decrease of cell viability and arrest of mitoses were not observed in cuhured lymphocytes within the range of the immunoinhibitory effect . The effect of colchicine derivatives was manifested as the inhibition of lymphocyte blastogenesis, which is probably the result of membrane transport blockade. (Authors' abstract) H. P. Kouu

Kink, R. M. and Gownw, T. V. (Department of Bioch~ry~ University of Mysore, Mysore 370006, India) Studies on snake venom enzymes: Part I - purification of ATPase, a toxic component of Ngja ngja venom and its inhibition by potassium gymnemate. Indian 1. Blochem . Biophys. 19, 132 (1982) . Stxrw-FOt.u purification of ATPase from Ngja naja venom was achieved by a single step process of CMSephadex C-23 column chromatography . Potassium gymnemate extracted from Gymnana sylvt strr, a folk medicinal plant for snake-bite, inhibited ATPase, a toxic component of the venom. ATP and gymnemate bind at the same site(a) as shown by spxtrofluorlmetric method . (Authors' abstract) H. P. KOLM