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At least 19 recordsLinked to original sources
PubMed1965

INSECT HORMONES.

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Animals↗
PubMed1967

Insect hormones: alpha ecdysone and 20-hydroxyecdysone in bracken fern.

The two major molting hormones of insects, alpha ecdysone and 20-hydroxyecdysone, were isolated in crystalline form from dry pinnae of the bracken fern, Pteridium aquilinum (L.) Kuhn. Three unidentified substances with molting hormone activity were also detected. Bracken is the first plant found to contain both of the major insect ecdysones, and it is the first known plant source of alpha ecdysone.

Chromatography, Thin Layer↗
PubMed2005

Stimulation of midgut stem cell proliferation and differentiation by insect hormones and peptides.

Stem cells derived from midguts of the caterpillar, Spodoptera littoralis, can be induced to multiply and differentiate in vitro. Ecdysone (E) and 20-hydroxyecdysone (20E) had a concentration-dependent effect: E was more active in cell proliferation and 20E in differentiation. Ecdysteroid receptors in midgut stem cell nuclei were stained with the antibody 9B9. In addition, alpha-arylphorin and four midgut differentiation factors (MDF) specifically stimulated proliferation and differentiation of stem cells, respectively. The activity of a panel of peptide growth factors and hormones on growth and metamorphosis of the insect midgut is discussed.

Animals↗
PubMed2005

Mass spectral signature for insect adipokinetic hormones.

Insect adipokinetic hormones (AKHs) are structurally similar. They consist of 8 to 10 amino acid residues, and are post-translationally modified at the N-terminus (pyroglutamic acid) and at the C-terminus (carboxyamide). They contain aromatic amino acids at position 4 (mostly Phe, in a few cases Tyr) and at position 8 (Trp). Position 9 is always Gly which is used in the octapeptides for the amidation, and the majority of the peptides have no charge. AKHs exhibit a characteristic ion signature both in matrix-assisted laser desorption/ionization (ion pair [M+Na](+)/[M+K]+) and in electrospray mass spectrometry ([M+H+K]2+, [M-17+H]+, [M+H]+, [M+Na]+, [M+K]+). Their high affinity for Na+ and K+ alkali cations is observed even after reversed-phase purification. AKHs rarely form doubly charged ions with protons or sodium while the [M+H+K]2+ ion is often abundant suggesting a special conformation of the larger metal ion complex possibly related to its size. Here, we present analyses of several AKHs of different insect species and discuss their ionization behavior with respect to their sequence. The mass spectral signature observed is useful for AKH detection from mixtures and so an unassigned 990.7 Da molecule was found in dragonfly which is currently under investigation.

Amino Acid Sequence↗
PubMed1971

Insect hormones and their derivatives as insecticides.

The hormonal control of moulting, reproduction, and diapause in insects has little or no relationship to any similar phenomena in other animals, and the hormones involved in these processes are unlike any known hormones of vertebrates.The availability of pure chemicals with high biological activity has permitted an astonishing increase in research on insect hormones. At present, understanding of insect endocrinology is far too incomplete to justify much speculation about the possibility of using insect hormones as insecticides. However, the preliminary studies discussed in this paper give reason for hope, and the results justify further effort.

Alkynes↗
PubMed2002

Foreign insect hormones stimulating the transcription of the ie-1 promoter of Bombyx mori nuclear polyhedrosis virus in vivo and in vitro.

Via a transient expression assay system, an experimental study was undertaken to characterize the effects of insect ecdysone and juvenile hormone analogue on the transient expression of the luciferase gene under the control of the immediate-early gene (ie-1) promoter of Bombyx mori nuclear polyhedrosis virus. The results demonstrated that the transcriptional activity of the ie-1 promoter was increased to a certain extent by different insect hormone treatments in uninfected insect cells or fifth instar silkworm larvae transfected with a plasmid containing a luciferase gene driven by the ie-1 promoter. By ecdysone treatment alone, an increase of 5-7 fold was reached in Bm-N, or Bm-5 cells, or in the early developmental stage of fifth instar larvae. By treatment with juvenile hormone analogue alone, about 2-fold, in Bm-N, Bm-5, and Sf-21 cells, or about 5-fold increase in the middle developmental stage of larvae was given, respectively. By co-treatment with ecdysone and juvenile hormone analogue, the incease was given between that of ecdysone and juvenile hormone analogue treatment alone. In addition, the synergistic effects of foreign/endogenous hormones on the activity of ie-1 promoter are discussed.

Animals↗
PubMed1968

Insect hormone activity of p-(1,5-dimethylhexyl)benzoic acid derivatives in Dysdercus species.

Derivatives of p-(1,5-dimethylhexyl)benzoic acid are juvenile hormone analogs with selective action on the hemipteran insects of the family Pyrrhocoridae. Their juvenile hormone activity is constant on five species of Dysdercus; it is about ten times lower on Pyrrhocoris, and no activity has been detected on hemipterans of some other families. Absence of profound species-specific variations in the activity suggests that the most active compounds of this type can be used as selective pesticides against all species of Dysdercus.

Animals↗
PubMed1996

Insect hormones in vertebrates: anabolic effects of 20-hydroxyecdysone in Japanese quail.

Ecdysteroids are hormones controlling cell proliferation, growth and the developmental cycles of insects and other invertebrates. They are occasionally present in various unrelated plants for no apparent reason; no phytohormonal function has yet been identified. In certain cases, ecdysteroids are accumulated to high levels in leaves, roots or seeds. Some ecdysteroid-containing plants have been known as medicinal plants for centuries. One of them, Leuzea carthamoides Iljin (Asteraceae), growing in Central Asia, contains 0.4% ecdysteroid in dry roots and 2% in seeds. A pharmacological preparation from this plant, "Ecdisten', is already available as a commercial preparation for its anabolic, tonic and other effects, for medical use (review). It remained problematic, however, whether ecdysteroids were truly responsible for these effects, because Leuzea contains a number of other biologically active compounds in addition to ecdysteroids. We extracted and purified ecdysteroids from the seeds of Leuzea. With 6 g of 96% 20-hydroxyecdysone (20E), we made a large-scale feeding assay with Japanese quail to find out whether ecdysteroid alone could duplicate the anabolic effects of the seeds. We found that the 96% ecdysteroid increased the mass of the developing quails in a dose-dependent manner, with the rate of increase proportional to the ecdysteroid content in the seeds; there was a 115% increase in living mass with 100 mg kg-1 of pure 20E compared with 109.5% increase with 100-180 mg kg-1 20E equivalents in the seeds. We conclude that the plethora of growth-promoting, vitamin-like effects induced in vertebrates by Leuzea is mediated by ecdysteroids.

Animals↗
PubMed1995

Key disulfide bonds in an insect hormone binding protein: cDNA cloning of a juvenile hormone binding protein of Heliothis virescens and ligand binding by native and mutant forms.

The hemolymph juvenile hormone binding protein (JHBP) from the early fifth instar larvae of Heliothis virescens (Lepidoptera, Noctuidae) has been purified, and three cDNA clones for this protein have been isolated from a fat body cDNA library constructed in bacteriophage lambda ZAP XR. The deduced amino acid sequence of the full-length clone predicts a mature protein consisting of 224 residues, a molecular mass of 24,976 Da, and a pI of 5.29. Comparison of the amino acid sequence to that of the previously described JHBP from Manduca sexta shows 51% overall identity with highly conserved N- and C-terminal regions. One of the three clones bound photoactivatable analogs of juvenile hormones with much lower affinity than the other two. This clone had Phe150 in place of the expected Cys150 conserved in other JHBP clones. The F150C mutant of this clone regained native binding affinity. For native Hvir-JHBP, the affinity for [3H]JH I was lower under reducing conditions (87 nM) relative to a 40 nM affinity under nonreducing conditions. The importance of pairs of Cys residues was addressed by preparing Cys to Ala mutants at each site. Expressed proteins were tested for binding affinity by photoaffinity labeling with tritium-labeled JH analogs and by binding assays using (10R,11S)-[3H]JH I. Curiously, the C150A mutant retained full activity, implying that the aberrant C150F was dysfunctional due to steric hindrance rather than to a missing disulfide linkage. Likewise, C29A and C194A had binding affinities unchanged from that of the full-length wild-type clone.(ABSTRACT TRUNCATED AT 250 WORDS)

Affinity Labels↗