Enzymatic synthesis of insect juvenile hormones

Reibstein, David; Law, John H.

doi:10.1016/0006-291x(73)91083-8

Cited by 31 publications

(8 citation statements)

References 8 publications

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“…Two nanomoles of a-amino-butyric acid was added to each sample prior to hydrolysis as an internal standard. Each peptide was hydrolyzed by HC1 gas in the presence of phenol at 105°C for 24 h. The amino acid ratios for ATAA were: Glu (0.9), Gly (0.9), Arg (1.0) Thr (l.O), Ala (1.2), Val (0.9), Nle (2.1), and Phe (1.0). The amino acid ratios for ATANA were: Glu (0.9), Gly (0.9), Arg (l.O), Thr (l.O), Ala (1.2), Val (0.9), Nle (2.1), and Phe (1.0).…”

Section: Methodsmentioning

confidence: 99%

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Stimulation of juvenile hormone biosynthesis by analogues of a Manduca sexta allatotropin: In vitro studies

Unni

Bhaskaran

Dahm

et al. 1991

Arch Insect Biochem Physiol

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Two analogues of a Manduca sexta allatotropin (Mas-AT) were synthesized. They correspond to the active fragment, amino acids 5-13, of the natural Mas-AT with substitution of norleucine for methionine. ATANA has the structure Val-Glu-Nle-Nle-Thr-Ala-Arg-Gly-Phe-NH2, ATAA is acetylated at the N-terminus. Allatotropic potency was evaluated by measuring the in vitro rates of juvenile hormone (JH) biosynthesis in corpora allata (CA) of M. Sexta. At a concentration of 20 nM, ATANA and ATAA increased JH production in day 0, day 1, and day 3 adult female CA by a factor of 3-8. Larval CA were not affected. These results correspond to activities reported for the natural Mas-At. ATANA did not stimulate pharate adult female CA to produce JH. Stimulation of female CA with ATANA was reversed when the CA were transferred to fresh medium while stimulation with ATAA under the same condition persisted. Exogenous farnesoate was converted to JH-III at a rate exceeding the highest ATANA-stimulated rate. ATANA in addition to farnesoate did not increase JH-III production, but increased JH-II production in addition to the already high production rate for JH-III. It is inferred that Mas-AT stimulates a rate-limiting enzyme in the biosynthesis of farnesoate and its homologues but does not affect epoxidation and methylation.

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Section: Methodsmentioning

confidence: 99%

“…If the terminal two enzymes of JH biosynthesis [24,25] are involved in the activation of JH biosynthesis by ATA, conversion of exogenous farnesoate to JH-I11 might be stimulated by ATA also. Day 3 CA were incubated in a medium containing farnesoic acid with or without ATANA.…”

Section: Effect Of Atana In the Presence Of Farnesoatementioning

confidence: 99%

Stimulation of juvenile hormone biosynthesis by analogues of a Manduca sexta allatotropin: In vitro studies

Unni

Bhaskaran

Dahm

et al. 1991

Arch Insect Biochem Physiol

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“…Although the occurrence of JHAMT in the CA has long been recognized by radiochemical assays (23,24), neither the protein nor its gene has been isolated from any insect. In this study, we have isolated by FDD a cDNA that encodes an SAM-dependent MTase from the CA of B. mori.…”

Section: Discussionmentioning

confidence: 99%

Juvenile hormone acid methyltransferase: A key regulatory enzyme for insect metamorphosis

Shinoda

Itoyama

2003

Proc. Natl. Acad. Sci. U.S.A.

308

321

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“…In these two cases, the principle hormone was identified as the lower homologue methyl 10,11epoxy-3,7,1 I-trimethyl-trans-trans-2,6-dodecadienoate (C16 juvenile hormone). The carboxylic acid ester group, which appears to be unique among known animal hormones, probably depends solely on the S-methyl group of exogenous L-methionine as its methyl source (Pratt & Tobe, 1974a,b), possibly through the formation of S-adenosylmethionine (Reibstein & Law, 1973).…”

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confidence: 99%

The influence of substrate concentrations on the rate of insect juvenile hormone biosynthesis by corpora allata of the desert locust in vitro

Tobe

Pratt

1974

Biochemical Journal

289

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The rate at which isolated corpora allata of adult female Schistocerca gregaria incorporate [(3)H]farnesenic acid and [(14)C]methionine into C(16)juvenile hormone in vitro was examined at different concentrations of farnesenic acid, methionine, O(2) and H(+) ions. Maximum juvenile hormone biosynthesis is obtained at a farnesenic acid concentration of 20mum. The range of optimum l-methionine concentrations (0.1-0.4mm) encompasses the physiological concentration of this substrate in the haemolymph. Hormone biosynthesis is dependent on O(2), but is not stimulated by hyperbaric oxygen tension. The glands had a maximum synthetic activity at pH8.0, but their activity was more reproducible in the the physiological range pH7.0-7.5. At pH6.5 and less, the synthetic ability was considerably decreased. The relative incorporations of the labelled substrates into methyl farnesoate and C(16) juvenile hormone indicate that [(3)H]farnesenic acid comes into isotopic equilibrium within the gland more rapidly than [(14)C]methionine. The incorporations into methyl farnesoate become stoicheiometric after 20min incubation and into C(16) juvenile hormone after a further 10min. Labelled juvenile hormone is detectable after 10min incubation and the rate of incorporation is constant for up to 4h. It is proposed that the described method may be usefully employed to assess the physiological changes in the enzymic competence of the glands to effect the last two stages in C(16) juvenile hormone biosynthesis.

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Enzymatic synthesis of insect juvenile hormones

Cited by 31 publications

References 8 publications

Stimulation of juvenile hormone biosynthesis by analogues of a Manduca sexta allatotropin: In vitro studies

Stimulation of juvenile hormone biosynthesis by analogues of a Manduca sexta allatotropin: In vitro studies

Juvenile hormone acid methyltransferase: A key regulatory enzyme for insect metamorphosis

The influence of substrate concentrations on the rate of insect juvenile hormone biosynthesis by corpora allata of the desert locust in vitro

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