摘要:

AbstractAn in vitro bioassay suitable for routine use to investigate hypertrehalosemic hormone (HTH)‐dependent trehalose biosynthesis was developed for the cockroach fat body.Blaberus discoidalisfat bodies were isolated and divided so that eight matched pieces from a single tissue could be compared for multiple control and experimental treatments. Optimum incubation conditions and the properties of HTH‐dependent trehalose synthesis were determined. Dose‐response studies determined an EC50of 0.044 nM HTH for male fat body and 0.16 nM HTH for female tissue. HTH increased trehalose production by male fat body 3‐fold compared to only a 67% maximum increase by the female tissue, and only the male tissue was used in subsequent studies. Fat body required only 5‐min exposure to HTH for maximum trehalose production for 1 h. Trehalose synthesis was inhibited by ≥ 15 mM trehalose in the incubation medium. The fat body showed a developmental increase in trehalose synthesis in vitro that was reflected by hemolymph trehalose in vivo. Basal and HTH‐related trehalose synthesis were low between days 0 and 10, increased 3‐fold by day 20, and were high thereafter. These studies have established baseline data for future investigations to identify the signal transduction mechanisms involved in HTH regulation of fat body metabolism. © 1995

ISSN:0739-4462    

DOI:10.1002/arch.940280402

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

年代:1995

数据来源: WILEY

摘要:

AbstractIn vitro bioassays were used to analyze the metabolism of the 11‐dodecenoic acid (11‐DDNA) by microsomes prepared fromDrosophila melanogasterRalDDTRstrain. 11‐DDNA is metabolized to 11,12‐epoxylauric acid (epoxyLA) in a NADPH‐dependent way. The microsomal production of epoxyLA reaches a plateau very quickly, suggesting the occurrence of an enzyme inactivation process. After incubation of microsomes with (1‐14C)11‐DDNA, three proteins of Mr ≈︁ 50 kDa were labeled. 11‐DDNA inhibits the microsomal metabolism of lauric acid and 7‐ethoxycoumarin in a time and NADPH‐dependent process. An inhibition of metabolites generated from DDT and testosterone was also obtained but at higher concentrations. These results are discussed according to the fact that RalDDTRis an insecticide resistant strain characterized as a high metabolizer of the insecticide DDT and also of lauric acid, testosterone, and ethoxycoumarin.

ISSN:0739-4462    

DOI:10.1002/arch.940280403

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

年代:1995

数据来源: WILEY

摘要:

AbstractChanges in the activity of over 20 enzymes of intermediary metabolism in 15°C or −4°C acclimated goldenrod gall moth (Epiblema scudderiana) and gall fly (Eurosta solidaginis) larvae were measured. Increased activities of glyco‐genolytic and hexose monophosphate shunt enzymes in cold‐acclimatedEpiblema scudderianasuggest a role for coarse control in the conversion of glycogen reserves into glycerol cryoprotectant synthesis. InEurosta solidaginis, high glycogen phosphorylase activity with decreased activities of glycolytic enzymes may account in part for the temperature‐dependent switch from glycerol to sorbitol synthesis in these larvae upon cold acclimation. Isoelectric focusing analyses of five enzymes in overwinteringEpiblema scudderianarevealed transient mid‐winter changes in the isoelectric points of phosphofructokinase and pyruvate kinase, suggesting seasonal changes in the phosphorylation state of these enzymes. A distinct developmental pattern of aldolase isozymes suggests a role for a new isozyme during overwintering or upon spring emergence. Regulation of metabolism by changes in enzyme activities is indicated for both larvae. © 1995 Wil

ISSN:0739-4462    

DOI:10.1002/arch.940280404

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

年代:1995

数据来源: WILEY

摘要:

AbstractThe proteinases in the midguts of three scarab white grub species,Lepidiota noxia, L. negatoria, andAntitrogus consanguineus, were investigated to classify the proteinases present and to determine the most effective proteinase inhibitor for potential use as an insect control agent. pH activity profiles indicated the presence of serine proteinases and the absence of cysteine proteinases. This was confirmed by the lack of inhibition by specific cysteine proteinase inhibitors. Trypsin, chymotrypsin, elastase, and leucine aminopeptidase activities were detected by using specific synthetic substrates. A screen of 32 proteinase inhibitors produced 9 inhibitors of trypsin, chymotrypsin, and elastase which reduced proteolytic activity by greater than 75%. © 1995 Wiley‐Liss, I

ISSN:0739-4462    

DOI:10.1002/arch.940280405

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

年代:1995

数据来源: WILEY

摘要:

AbstractThe influence of dietary allelochemical on ecdysone 20‐monooxygenase activity was studied in the fall armyworm,Spodoptera frugiperda(J.E. Smith). Feeding the indoles (indole‐3‐carbinol, indole‐3‐acetonitrile), flavonoids (flavone, β‐naphthoflavone), monoterpenes (menthol, menthone, peppermint oil), and a coumarin (xanthotoxin) to the larvae stimulated midgut microsomal ecdysone 20‐monooxygenase activity from 28 to 200% as compared with the controls. β‐Naphthoflavone was the most potent inducer among those tested. Phenobarbital, a well‐known cytochrome P450 inducer, also caused a 2‐fold increase in the microsomal ecdysone 20‐monooxygenase activity. Ecdysone 20‐monooxygenase activity was 2.7‐fold higher in the microsomal fraction than in the mitochondrial fraction isolated from larval midguts. Microsomal ecdysone 20‐monooxygenase activity was highest in the fat body, followed by the midgut and Malpighian tubules. Tissue localization and enzyme inducibility were different between ecdysone 20‐monooxygenase and xenobiotic‐metabolizing cytochrome P450 monooxygenases, including aldrin epoxidase, biphenyl hydroxylase, methoxyresorufinO‐demethylase, 7‐ethoxycoumarinO‐deethylase,p‐chloro‐N‐methylanilineN‐demethylase, and phorate sulfoxidase

ISSN:0739-4462    

DOI:10.1002/arch.940280406

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

年代:1995

数据来源: WILEY

摘要:

AbstractHydrocarbons on the puparia of flesh flies,Sarcophaga crassipalpis, were analyzed to determine whether the abundance of hydrocarbons on puparia from diapausing individuals (twice the amount extracted from puparia of nondiapausing individuals) was the consequence of an increase in deposition of select hydrocarbons or an overall increase in deposition. Hydrocarbons from the puparia of both diapausing and nondiapausing individuals are saturated and range in chain length from 25 to 33 carbons. GC‐MS analyses indicate that the hydrocarbon fraction containsn‐, terminally and internally branched monomethyl‐, and 3,x‐, 5,x‐ and internally branched dimethylalkanes. The diapausing and nondiapausing empty puparia contained 39.4 and 42.9%n‐alkanes, 46.5 and 44.7% monomethylalkanes, and 9.5 and 8.5% dimethylalkanes, respectively. No major differences in the percent composition of the different hydrocarbons were noted between the two groups. This suggests that the amount of hydrocarbon, rather than the composition, contributes to the lower transpiration rates observed in diapausing pupae. © 1995 Wil

ISSN:0739-4462    

DOI:10.1002/arch.940280407

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

年代:1995

数据来源: WILEY

摘要:

AbstractCytosolic superoxide dismutase (SOD) of the onion maggot,Delia antiqua, was purified to apparent homogeneity by ammonium sulfate fractionation followed by anion exchange, hydrophobic interaction, and gel filtration chromatographies. Native molecular mass was estimated as 32,000 daltons. SDS‐PAGE revealed only one subunit of 16,000 daltons, indicating that SOD is a homodimer. Isoelectric focusing revealed 3 charge isomers of pls 5.3, 5.5, and 5.7. The specific activity of purified SOD was 4,250 U/mg protein. A monoclonal antibody (MAb, aSOD2B7) raised againstDeliaSOD recognized only SOD of the same genus, but another MAb (aSOD1H11) recognized SOD ofDrosophila melanogasteras well. © 1995 Wiley‐Liss,

ISSN:0739-4462    

DOI:10.1002/arch.940280408

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

年代:1995

数据来源: WILEY

摘要:

AbstractThe acidic glutathione S‐transferases from a CSMA (susceptible) strain and a Cornell‐R (resistant) strain of houseflies were purified and separated utilizing affinity chromatography followed by chromatofocusing. Nine fractions were isolated from each house fly strain. Fraction 1 had the highest 1‐chloro‐2,4‐dinitrobenzene vs. 1,2‐dichloro‐4‐nitrobenzene ratio (CDNB/DCNB ratio) in both strains and the ratio of all the other fractions tended to decrease as the isoelectrical points decreased except for fractions 4 and 9. Most fractions from the CSMA strain had higher CDNB conjugation activities than the fractions from the Cornell‐R strain, but all the fractions from the CSMA strain had lower DCNB conjugation activities than fractions from the Cornell‐R strain. Steady‐state kinetics of all the fractions were examined. The Km values obtained from both strains ranged from 0.36 to 1.12 mM, while the Vmax value ranged from 3.0 to 32.6 μmol/min/mg. In the 100,000 g supernatant, the CDNB specific activities in the CSMA strain was about 1/3 of the activity in the Cornell‐R strain but it was about 1.5‐fold following affinity chromatography. The specific activity for DCNB measured in the CSMA strain was only 1/5 of the activities of the Cornell‐R strain in the 100,000 g supernatant, but was about the same after affinity chromatography. The difference was due to the selectivity of the affinity column used in the current s

ISSN:0739-4462    

DOI:10.1002/arch.940280409

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

年代:1995

数据来源: WILEY

ISSN:0739-4462    

DOI:10.1002/arch.940280401

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

年代:1995

数据来源: WILEY