@misc{KortPeterKoopmanschap1983, author = {Kort, C. A. D. de and Peter, Martin G. and Koopmanschap, A. B.}, title = {Binding and degradation of juvenile hormone III by haemolymph proteins of the Colorado potato beetle: a re-examination}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-16777}, year = {1983}, abstract = {The haemolymph of the adult Colorado potato beetle, Lepinotarsa decemlineata Say, contains a high molecular weight (MW > 200,000) JH-III specific binding protein. The Kd value of the protein for racemic JH-III is 1.3 ± 0.2 × 10-7 M. It has a lower affinity for racemic JH-I and it does not bind JH-III-diol or JH-III-acid. The binding protein does discriminate between the enantiomers of synthetic, racemic JH-III as was determined by stereochemical anaysis of the bound and the free JH-III. Incubation of racemic JH-III with crude haemolymph results in preferential formation of (10S)-JH-III-acid, the unnatural configuration. The JH-esterase present in L. decemlineata haemolymph is not enantioselective. It is concluded that the most important function of the binding protein is that of a specific carrier, protecting the natural hormone against degradation by esterases. The carrier does not protect JH-I as efficiently as the lower homologue.}, language = {en} } @misc{PeterStuppLentes1983, author = {Peter, Martin G. and Stupp, Hans-Peter and Lentes, Klaus-Ulrich}, title = {Umkehr der Enantioselektivit{\"a}t bei der enzymatischen Hydrolyse von Juvenilhormon als Ergebnis einer Proteinfraktionierung}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-17001}, year = {1983}, abstract = {Aus dem Inhalt: Die Juvenilhormone 1a-c werden im Blut von Insekten enzymatisch zu den biologisch inaktiven Sluren hydrolysiert. Bei der Hydrolyse von racemischem 1c im Blut der Wanderheuschrecke Locusta migratoria wird ein Umsatz von 40-60\% erreicht. Das unumgesetzte Edukt enth{\"a}llt einen {\"U}berschuß an nat{\"u}rlich konfiguriertem (10R)-1c (e.e. 47.2\%). Wir konnten zeigen, daß das in der H{\"a}molymphe vorhandene Hormon-Bindungsprotein bevorzugt mit (10R)- 1c assoziiert.}, language = {de} } @misc{Peter1980, author = {Peter, Martin G.}, title = {Products of in vitro oxidation of N-acetyldopamine as possible components in the sclerotization of insect cuticle}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-16759}, year = {1980}, abstract = {[1-14C]-N-Acetyldopamine (NADA) was oxidized in the presence of methyl [3-3H]-β-alanate with mushroom tyrosinase. The complex mixture of reaction products was partly resolved by chromatographic procedures and analyzed by spectroscopic methods. Methyl-β-alanate is incorporated to only a small extent into oxidation products of NADA which inter alia are presumed to be oligomeric hydroxyquinones. After oxidation of [1-14C, 2-3H]-NADA with preparations from tanning Manduca sexta pupal cuticle, N-acetylnoradrenalin was identified as one of the products. Binding of radioactivity to melanin-like material was also observed. These results suggest that oxidation products different from those formulated usually for the crosslinkages between protein amino groups and N-acetyldopaquinone are deposited in darkly brown coloured insect cuticles during sclerotization.}, language = {en} }