Inheritance and mapping of isoenzymes in pea (Pisum sativum L.)

Summary Three isoenzyme systems (amylase, esterase and glutamate oxaloacetate transaminase) were examined in seeds of pea (Pisum sativum L.) and shown to give clear variation in their band patterns on gel electrophoresis between different lines. The inheritance of these isoenzyme systems, and the location of their genes on the pea genome was investigated. Reciprocal crosses were made between lines, F2 seeds were analysed for segregation in the band patterns of the isoenzymes, and F2 plants were investigated to find linkage between the genes for these isoenzymes and genes for selected morphological markers. The results obtained showed that each of the investigated isoenzyme systems is genetically controlled by co-dominant alleles at a single locus. The gene for amylase was found to be on chromosome 2, linked to the loci k and wb (wb ... 9 ... k ... 25 ... Amy). The gene for esterase was found to be linked with the gene Br (chromosome 4) but the exact location is uncertain because of the lack of the morphological markers involved in the cross. The gene for glutamate oxaloacetate transaminase was found to be on chromosome 1 and linked with the loci a and d (a... 24... Got... 41 ... d).     

Kinetics of early insulin response by the isolated and perfused rat pancreas. Suggestion for two different actions of glucose on the insulin releasing process.

The permissive action of glucose (or glyceraldelhyde) is necessary to the glucagon induced insulin release. By collecting every 15 seconds the venous effluent of the perfused and isolated rat pancreas it was observed that the insulin response to glucagon (2 microgram/ml) was immediate if the pancreas was preperfused with low concentration of glucose (5 mM) or glyceraldelhyde (2,5 mM). On the other hand glucagon alone elicited no response, and the insulin discharge occurred 60 to 90 seconds after the addition of glucose (5 mM) or glyceraldelhyde (2,5 mM) this time being probably allowed to the metabolism of the sugar. The pancreatic response to 15 mM glucose occurred also 60 to 90 seconds after the stimulus. On the other hand when the medium contained a low concentration of glucose (or glyceraldelhyde) increasing the glucose concentration by 10 mM provoked an immediate insulin release. This suggests that glucose has two actions differing by their lag phase. One, "permissive", apparent after some delay, mimicked by glyceraldelhyde, necessary for glucagon induced insulin release, is mediated probably by the metabolic products of the sugar. The second, "triggering", initiates instantaneously the insulin release but appears dependent on the first action.     

Search for MHC-associated genes in human: five new genes centromeric to HLA-DP with yet unknown functions

Taking advantage of five mouse genomic or cDNA probes [KE5(probe 14), KE4 (probe11), KE3 (probe7), KE2 (probe5), and SET] mapped on the H-2K region in mouse, we have identified and localized homologues of these five genes in the human major histocompatibility complex region (HKE5, HKE4, HKE3, HKE2, and HSET, respectively). Cosmid cloning and pulsed field gel electrophoresis analyses indicated that a human homologous gene, HKE5, is located 10 kilobases (kb) centromeric of the 2(XI) collagen (COL11A2) gene followed by HKE4. HKE3, closely linked to HKE2, is located 170 kb centromeric of HKE4. Furthermore, HSET is located 50 kb centromeric of HKE2. This gene organization outside the DP subregion is completely identical to that of the mouse H-2K region centromeric of I-Pb 3, a mouse homologue of the DPB gene, except the lack of genes corresponding to the H-2K and -K2 genes in human.     

Production of L-phenylacetyl carbinol by immobilized yeast cells: II. Semicontinuous fermentation

The cyclic, semicontinuous production of L-phenylacetyl carbinol (L-PAC) from a benzaldehyde substrate by Saccharomyces cerevisiae ATCC 834 immobilized in calcium alginate beads was substantially enhanced to about 4.5 g/L in a second cycle by reactivation in fresh medium for 24 h, following an earlier 24-h period of production from substrate. Intermittent feeding of benzaldehyde was employed (four doses in 3 h). In subsequent similar cycles, however, the production returned to that produced in the first cycle, viz. L-PAC concentration of 2-3 g/L in the medium. Production of L-PAC was also increased by adaptation of the cells over 200 h of exposure to the benzaldehyde substrate (compared to wild-type cells) and by continuous (as compared to intermittent) feeding of the substrate. A liter as great as 10 g/L was obtained with wild-type cells by continuous feeding of benzaldehyde over 6 h. Immobilization not only protected the cells from toxic effects of substrate but also permitted them to be used during 7 cycles of semicontinuous operation over more than 200 h.     

Peroxidase-mediated toxicity to schistosomula of Schistosoma mansoni

Guinea pig eosinophil peroxidase (EPO) was capable of killing schistosomula of Schistosoma mansoni in vitro when combined with hydrogen peroxide and a halide. Killing was measured by 51Cr release, by microscopic evaluation of viability, and by reinfection experiments in mice. Parasite killing was dependent on each component of the EPO-H2O2-halide system, was completely inhibited by catalase and azide, and was partially inhibited by cyanide. The EPO-mediated system required 10(-4) M H2O2 and 10(-4) M iodide at pH 7.0, and the schistosomula were killed with exposure to this system of less than 30 min at 37 degrees C. At pH 6.0, the EPO-mediated system showed significant cidal activity with 10(-6) M iodide. Canine neutrophil peroxidase (myeloperoxidase [MPO]) was also able to kill schistosomula in vitro in the presence of 10(-4) M H2O2 and 10(-4) iodide at pH 7.0 and pH 6.0. Physiologic concentrations of chloride (0.1 M) could substitute for iodide at pH 7.0 and pH 6.0 as the halide cofactor; however, at pH 7.0, a higher concentration of enzyme was required. These findings with isolated enzyme systems are compatible with a role for peroxidase in the host defense against schistosomula.     

Stereoselective epoxidation of phenyl allyl ether by alkene-utilizing bacteria

Summary Eighteen newly isolated ethene- and propene-utilizing bacteria were screened for the ability to produce phenyl glycidyl ether, a common precursor for the synthesis of beta blockers, from phenyl allyl ether. These organisms included Aerococcus, Alcaligenes, Micrococcus and Staphylococcus spp. and a variety of Gram-negative, Gram-positive and Gram-variable mesophilic rods/coccobacilli not yet identified. The majority of ethene- and propene-grown cultures (14 strains) accumulated phenyl glycidyl ether (0.4–1.7 mm) as the sole oxidation product. The bioconversions with the three most promising ethene-utilizers (M26, M90C, M93A) were scaled-up to yield essentially optically pure (enantiomeric excess = 93%) S-(+)-phenyl glycidyl ether. This is currently under investigation for commercial production of optically pure beta blockers. Offprint requests to: M. Mahmoudian     

Nucleic Acid Related Compounds: A Convenient Synthesis of 3-Deazauridine Analogues

Abstract

A novel synthesis of 3-deazapyrimidine glycosides utilizing pyridine-2(1H)-ones or their sodium salts and α-halomonosugars namely D-glucose or D-galactose as starting components is described.