ISSN:0739-4462    

DOI:10.1002/1520-6327(1996)31:4<354::AID-ARCH940310402>3.0.CO;2-3

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1996

数据来源: WILEY

摘要:

AbstractPBAN (also termed melanization and reddish coloration hormone, MRCH) is a cerebral factor known to regulate sex pheromone biosynthesis and cuticular melanization in moths. In the present study we developed a quantitative method (based on computerized image analysis of cuticles) to determine the effect ofHelicoverpa zeaPBAN (Hez‐PBAN) on cuticular melanization and to study the structure‐activity relationship of the neuropeptide inSpodoptera littoralislarvae. The results indicate that Hez‐PBAN stimulates cuticular melanization in an interspecific manner, and that the minimal dose evoking formation of melanins is between 3–10 pmol/larva. Higher doses of Hez‐PBAN did not stimulate melanization any further. Examination of the structure‐activity relationship of Hez‐PBAN revealed that the first eight N‐terminal amino acids are not essential for the melanotropic activity and that the activity resides in the C‐terminal region. Within this region the C‐terminal amide was found to play a very important role. ©

ISSN:0739-4462    

DOI:10.1002/(SICI)1520-6327(1996)31:4<355::AID-ARCH1>3.0.CO;2-V

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1996

数据来源: WILEY

摘要:

AbstractThe 29 kDa protein from the larval epidermis of the tobacco hornworm,Manduca sexta, that specifically bound photoaffinity analogs of JH I and JH II was produced by a recombinant baculovirus (rJP29). The higher of the two molecular weight forms made corresponded to a protein that could be formed by read‐through of the TGA termination codon to the following TAA. The previously reported, apparent high affinity binding of [methyl‐3H]‐JH I by rJP29 as measured by the dextran‐coated charcoal (DCC) assay [Palli et al., Proc Natl Acad Sci USA 91:6191–6195 (1994)]was found to be artifactual due to endogenous cellular esterases that co‐purified with rJP29 through both DEAE cellulose and MonoQ chromatography. These esterases converted the 10–20 nM labelled JH to JH I acid and [3H]‐methanol during the 1 h incubation at room temperature. Additionally, DEAE fractions containing rJP29 or from wild‐type virus‐infected cells were found to bind nonspecifically high amounts of 12, 13‐3H]‐JH I acid in the DCC assay. Neither rJP29 nor the cellular esterases had JH esterase activity when assayed on a series of thioether surrogate substrates. When separated from these contaminating esterases either by hydroxylapatite or affinity chromatography, rJP29 showed little or no detectable binding of [12,13‐3H]‐JH I. Yet purified rJP29 bound EBDA, the photoaffinity analog of JH I; and this binding was prevented by retinol, JH I, methyl farnesoate, methoprene, and xanthophyll, but not by farnesol and 20‐hydroxyecdysone. Therefore, JP29 is not a high affinity JH rec

ISSN:0739-4462    

DOI:10.1002/(SICI)1520-6327(1996)31:4<371::AID-ARCH2>3.0.CO;2-Z

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1996

数据来源: WILEY

摘要:

AbstractVitellogenins (Vgs) and vitellins (Vns) were purified from reproductive female adult hemolymph (HL) and newly laid eggs of the bean bug,Riptortus clavatus. They were separated into two (Vg‐1 and 2) and three (Vn‐1′, Vn‐1, and Vn‐2) sub‐components, respectively, by ion exchange chromatography. Fused rocket immunoelectrophoresis using anti‐(Vn‐1) serum showed that they are distinguished clearly into two immunologically distinct groups, i.e., Vg‐1/Vn‐1/Vn‐1′ and Vg‐2/Vn‐2. SDS‐PAGE analysis showed Vn‐1 (Vn‐1′) and Vn‐2 have the same and/or smaller subunit component polypeptides as Vg‐1 and Vg‐2, respectively. Vn‐1′ has some lower molecular weight peptides than Vn‐1. Quantitative rocket immunoelectrophoretic analysis showed that Vg‐1 and Vn‐1 (plus V‐1′) were detected first on day 3 in the HL and day 4 in the ovary, respectively, after adult emergence, and increased by day 10 in non‐diapause female adults. Vg‐1 synthesis is induced in diapause female adults in 1 day after the treatment with juvenile hormone (JH) and JH analog (JHA) or in a few days after transfer fr

ISSN:0739-4462    

DOI:10.1002/(SICI)1520-6327(1996)31:4<395::AID-ARCH3>3.0.CO;2-V

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1996

数据来源: WILEY

摘要:

AbstractApolipophorin‐III (apoLp‐III) was purified from the haemolymph of adultHyphantria cunea(Drury) by KBr density gradient ultracentrifugation, gel filtration (Sephadex G‐100) and ion exchange chromatography (CM‐52), and its characteristics, molecular weight, tissue distribution, and sites of synthesis were examined. Molecular weight of apoLp‐III was estimated to be 18 kDa. By electrophoretic analysis on 10% gels of male and female haemolymph from diverse developmental stages, apoLp‐III was shown to be present in all stages.Western blotting was carried out to show that purified free apoLp‐III is identical to apoLp‐III associated with adult lipophorin. Immunological analysis also showed that apoLp‐III is present in the ovary and the testis and in the case of testis, apoLp‐III is heavily accumulated in the cyst. ApoLp‐III is synthesized in larval and adult fat body but not in adult testis. Autoradiography following incubation of [14C]apoLp‐III with testis showed that apoLp‐III was taken up into testi

ISSN:0739-4462    

DOI:10.1002/(SICI)1520-6327(1996)31:4<413::AID-ARCH4>3.0.CO;2-W

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1996

数据来源: WILEY

摘要:

AbstractIn the penultimate and last instar larvae ofSchistocerca gregaria, 20‐hydroxyecdysone (20E) makes up 74–84% of detected ecdysteroids in the females, and 63–74% in the males. Remaining ecdysteroids include ecdysone, a compound with HPLC and TLC retention times of makisterone A, and highly polar metabolites. Except for the last instar females, the contents of ecdysone and the unknown compound are higher in the solitary phase, while that of polar metabolites is higher in the gregarious phase. The phases also differ in that the molt‐inducing ecdysteroid peaks last longer in the gregarious than in the solitary larvae. Peak concentrations reach 3.0–4.0 μg 20E equiv./ml in penultimate female instar, 2.5–3.0 μg/ml in penultimate male instar, and 1.5–2.0 μg/ml in the last larval instar of both sexes. © 199

ISSN:0739-4462    

DOI:10.1002/(SICI)1520-6327(1996)31:4<427::AID-ARCH5>3.0.CO;2-S

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1996

数据来源: WILEY

摘要:

AbstractNeuropeptide content of the corpora cardiaca (CC) was studied in crowded (gregarious phase) and isolated (solitary phase)Locusta migratoria migratorioidesadults, using electrophoretic, chromatographic, and immunological techniques. Quantitative differences were found in the three neuropeptides investigated (neuroparsins, Lom‐OMP, and APRP). The amount of neuroparsin A was higher in the CC of crowded locusts. Neuroparsin B content of the CC was quite similar in isolated and crowded locusts, or in some cases slightly higher in the latter. The comparative amounts of the ovary maturating parsin, Lom‐OMP, in the CC were dependent on the sexual maturation of the locusts, being nearly similar in maturing isolated locusts and immature crowded locusts, but higher in crowded locusts when both phases were completely mature. The amount of AKH‐precursor related peptides (APRP) was markedly and consistently higher in the CC of isolated locusts. These findings are discussed in relation to other physiological and ecological phase‐dependent differences in locusts. © 1996 Wiley

ISSN:0739-4462    

DOI:10.1002/(SICI)1520-6327(1996)31:4<439::AID-ARCH6>3.0.CO;2-Q

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1996

数据来源: WILEY

摘要:

AbstractThe effects of the cystatins, human stefin A (HSA) and oryzacystatin I (OCI) on digestive cysteine proteinases of the Colorado potato beetle (CPB),Leptinotarsa decemlineata, and the black vine weevil (BVW),Otiorynchus sulcatus, were assessed using complementary inhibition assays, cystatin‐affinity chromatography, and recombinant forms of the two inhibitors. For both insects, either HSA and OCI used in excess (10 or 20 μM) caused partial and stable inhibition of total proteolytic (azocaseinase) activity, but unlike for OCI the HSA‐mediated inhibitions were significantly increased when the inhibitor was used in large excess (100 μM). As demonstrated by complementary inhibition assays, this two‐step inhibition of the insect proteases by HSA was due to the differential inactivation of two distinct cysteine proteinase populations in either insect extracts, the rapidly (strongly) inhibited population corresponding to the OCI‐sensitive fraction. After removing the cystatin‐sensitive proteinases from CPB and BVW midgut extracts using OCI‐ (or HSA‐) affinity chromatography, the effects of the insect “non‐target” proteases on the structural integrity of the two cystatins were assessed. While OCI remained essentially stable, HSA was subjected to hydrolysis without the accumulation of detectable stable intermediates, suggesting the presence of multiple exposed cleavage sites sensitive to the action of the insect proteases on this cystatin. This apparent susceptibility of HSA to proteolytic cleavage may partially explain its low efficiency to inactivate the insect OCI‐insensitive cysteine proteinases when not used in large excess. It could also have major implications when planning the use of cystatin‐expressing transgenic plants for the control of coleopteran pest

ISSN:0739-4462    

DOI:10.1002/(SICI)1520-6327(1996)31:4<451::AID-ARCH7>3.0.CO;2-Y

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1996

数据来源: WILEY

摘要:

AbstractThe multiple phosphorylation of ribosomal protein S6 appears to be required for prothoracicotropic hormone (PTTH)‐stimulated protein synthesis and ecdysteroidogenesis by the prothoracic glands ofManduca sexta. The present study investigated the role of protein phosphatase in these phenomena by analyzing the effects of pretreatment of prothoracic glands with the phosphatase inhibitors okadaic acid and calyculin A in both basal and PTTH‐stimulated glands. Okadaic acid or calyculin A treatment enhanced ribosomal S6 phosphorylation in control glands to a level similar to that observed with PTTH‐stimulated glands. This treatment also prevented S6 dephosphorylation but had no apparent synergistic effect on S6 phosphorylation in PTTH‐stimulated glands. Most importantly, okadaic acid or calyculin A treatment inhibited, rather than augmented, ecdysteroidogenesis in both PTTH‐stimulated and non‐stimulated glands. The composite data suggest that protein phosphatase activity sensitive to okadaic acid or calyculin A is required for PTTH‐stimulated ecdysteroidogenesis. © 1996 W

ISSN:0739-4462    

DOI:10.1002/(SICI)1520-6327(1996)31:4<465::AID-ARCH8>3.0.CO;2-U

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1996

数据来源: WILEY

ISSN:0739-4462    

DOI:10.1002/1520-6327(1996)31:4<::AID-ARCH940310401>3.0.CO;2-W

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1996

数据来源: WILEY