Hans Emmerich

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This paper describes two ecdysone-deficient, recessive-lethal mutants,lethal(1)giant ring gland (grg) andlethal(1)suppressor of forked mad-ts (mad-ts: Jürgens and Gateff 1979) and compares their ecdysteroid titers with that of the wild-type. Mutant larvae show a much reduced ecdysteroid content, amounting to 1/10 to 1/30 of the wild-type values, but never a(More)
Inokosteron-26-oic acid was coupled to thyroglobulin in aqueous pyridine by a water-soluble carbodiimide. After exhaustive dialysis and gel filtration on Sephadex G-25 in the presence of sodium dodecylsulfate, a coupling ratio of 164 haptens per molecule of thyroglobulin was determined. In all three animals injected with the conjugate, ecdysone-binding(More)
Third larval instar hemolymph of the fruitflyDrosophila hydei did not metabolize juvenile hormone (JH) at all developmental stages. In contrast, prepupal and pupal body fluid showed JH-esterase activity with a maximum at 4 h after puparium formation. In body wall and fat body of all developmental stages investigated, JH-metabolic activity was found. In both(More)
Radiolabelled juvenile hormone I (3) was prepared in an optically pure form by an enzymatic method using the capacity of accessory sex gland homogenates from maleHyalophora cecropia to transfer the methyl group of S-adenosyl-L-methionine to the carboxylic acid function of the (10R, 11S)-enantiomer of racemic presursor2; the specific activity of3 is higher(More)
The association of ponasterone A (PNA) and 20-hydroxyecdysone with Kc cells is commensurate with their biological activity on this Kc cell line, the physiological activity ratio for PNA, 20-hydroxyecdysone and ecdysone is 1 : 50 : 2000, resp. Both association and release of [3H]-PNA are temperature-dependent, the activation energy was calculated as 16.7 cal(More)
1. A simple and rapid method is described for the isolation and purification of oocyte vitellin ofLocusta migratoria. The isolated protein has been shown to be homogenous by polyacrylamide gel electrophoresis, isoelectric focusing, sedimentation analysis and in the Ouchterlony test. 2. The yolk protein stains with Sudan black and lipid crimson, it reacts(More)
A model for the phase transition between partial wetting and dewetting of a substrate has been formulated that explicitly incorporates the hydrodynamic flow during the dewetting process in 1+1 dimensions. The model simulates a fluid layer of finite thickness on a substrate in coexistence with a dry part of the substrate and a gas phase above the substrate.(More)