A5086095963- Insect Resistance and Genetics
- Neurobiology and Insect Physiology Research
- Insect Utilization and Effects
- Insect and Arachnid Ecology and Behavior
- Mosquito-borne diseases and control
- Insect Pest Control Strategies
- Insect and Pesticide Research
- Insect symbiosis and bacterial influences
- Phytoplasmas and Hemiptera pathogens
- Insect-Plant Interactions and Control
- Viral Infectious Diseases and Gene Expression in Insects
- Entomopathogenic Microorganisms in Pest Control
- Invertebrate Immune Response Mechanisms
- Malaria Research and Control
- Transgenic Plants and Applications
- Studies on Chitinases and Chitosanases
- Research on Leishmaniasis Studies
- Plant and animal studies
- Aquaculture Nutrition and Growth
- Enzyme Production and Characterization
- Trypanosoma species research and implications
- Plant Virus Research Studies
- Cocoa and Sweet Potato Agronomy
- Antimicrobial Peptides and Activities
- Algal biology and biofuel production
University of Colorado Anschutz Medical Campus
2018-2024
University of Colorado Denver
2021
Vector (United States)
2019
U.S. Horticultural Research Laboratory
2015-2018
United States Department of Agriculture
1990-2016
Medizinische Hochschule Hannover
2015
Agricultural Research Service
2014
University of California, Riverside
2014
Florida Medical Entomology Laboratory
2003-2013
University of Florida
2003-2013
A peptide that inhibits egg development in mosquitoes (oostatic factor) has been purified from the ovaries of female Aedes aegypti. The factor is a decapeptide with molecular mass 1047.6. primary sequence determined as NH2-Tyr-Asp-Pro-Ala-Pro-Pro-Pro-Pro-Pro-Pro-COOH spectra recorded on quadrupole Fourier transform instrument. amino acid exhibits correlation to mammalian, plant, and several viral proteins. Injection synthetic analogs into mosquitoes, biting midges, flies, fleas inhibited...
When potato Q‐enzyme converts amylose into an amylopectin‐like molecule, the action is by a random, endo‐type transglycosylation of substrate chains. Inter‐chain transfer takes place during formation amylopectin branch linkage. This seen in experiments which radioactive label was transferred between substrates disparate molecular weight. Intra‐chain transfer, leading to linkage, not excluded these experiments. The minimum length chain that can act as acceptor reaction, under experimental...
Abstract. Phlebotomus papatasi (Scopoli) is susceptible to infection with Leishmania major Yakimov & Schokov and resistant L.donovani Laveran Mesnil. The possibility that susceptibility depends on midgut levels of trypsin chymotrypsin‐like (esterolytic) enzymes was investigated. Infection L. reduced the trypsin‐like activity 93.5% 86% control value at 20 30 h post feeding increased it 106% 52 h. 64% 73% feeding. overall amount in L.major infections 50% 34% 184% Only one separated by gel...
Q‐Enzyme, the enzyme that synthesizes 1,6‐α‐glucosidic branch linkages of amylopectin, has been purified from potato to near homogeneity. The molecular weight is 85000. active a monomer, with molar activity at pH 7.0 and 24 °C 15. energy activation 25 kJ/mol below 15 °C, changing sharply 63 above temperature. Enzyme not affected by Mg 2+ or ATP. There are about 11 readily titratable sulfhydryl groups per molecule. evidence single protein entity, without hydrolytic towards amylose, contrasts...
Abstract Female Aedes aegypti that were fed blood and immediately abdominally ligated did not deposit yolk. Injection of 20‐hydroxyecdysone (1.5–5.0 ng) or topical application juvenile hormone (JH) analogue methoprene (25 pg) induce vitellogenesis in these abdomens. When blood‐gorged abdomens treated with both hormones, however, was stimulated 60% animals. Rocket immunoelectrophoresis indicated vitellin concentration per follicle animals similar to intact controls. first injected a crude...
Abstract A quantitative and highly specific assay for the determination of trypsinlike chymotrypsinlike enzymes in insects has been developed. The is based on binding [1,3‐ 3 H]diisopropylfluorophosphate to enzymes. Trypsinlike can be determined specifically presence 10 mM TPCK (tosylamide‐2‐phenylethyl chloromethyl ketone; chymotrypsin inhibitor) TLCK (tosyl‐L‐lysine ketone HCI; trypsin inhibitor). easily detect 65 ng either or midgut homogenates whole extracts many insect species. Using...
The gut receptor of trypsin-modulating oostatic factor (TMOF), a decapeptide hormone that regulates trypsin biosynthesis in the mosquito gut, has been characterized. binding TMOF to membranes reached maximum at pH 7.4 and 24 degrees C. No was observed 2.5 declined rapidly 8.0. At equilibrium, 60 min A synthetic complementary NH2-Ile-Leu-Gly-Arg-Gly-Gly-Gly-Gly-Gly-Gly-COOH (FOMT) for successfully competed with receptor, specifically bound (Kd = 4 microM Kassoc x 10(5) M-1). characterized...
Abstract The synthesis of proteolytic enzymes in the fat body and midgut female Culex nigripalpus was followed. effects brain factor(s) RNA levels were correlated with enzymes. Trypsinlike activity C. accounted for 80% total activity, whereas chymotrypsinlike 5–7% activity. Synthesis porteases reached a peak at 35 h 22 after blood meal, respectively. In body, enzyme fell to low level 30 but 58 meal. presence protease time vitellogenin indicated that processing not done this tissue. Fat...
Abstract Proteolytic enzyme biosynthesis in the midgut of 4th instar larva Heliothis virescens is cyclical. Protease activity increases immediately after molt from 3rd to larvae and declines just before into 5th instar. Characterization proteases using soybean tryspin inhibitor (SBTI) Bowman Birk Inhibitor (BBI) 4‐(2‐aminoethyl)benzensulfonylfluoride (AEBSF) N‐tosyl‐L‐phenylalanine chloromethylketone (TPCK) indicate that protease mostly trypsinlike (80%) with a small amount chymotrypsinlike...
Abstract Trypsin and chymotrypsin‐like enzymes were detected in the gut of Aedes aegypti four larval instar pupal developmental stages. Although overall amount trypsin synthesized was 2‐fold higher than chymotrypsin, both are important food digestion. Feeding Aea ‐Trypsin Modulating Oostatic Factor (TMOF) to Ae. Culex quinquefasciatus larvae inhibited biosynthesis gut, stunted growth development, caused mortality. ‐TMOF induced mortality , Cx. nigripalpus Anopheles quadrimaculatus...
Abstract Injection of partially purified oostatic hormone (0.7 μg) into female Aedes aegypti inhibited egg development, proteolytic enzyme activity, and blood digestion in the midgut, whereas control injections saline or insulin chain A did not affect these processes. Oostatic given by enema, on other hand, inhibit indicating that acts outside midgut. single injection caused a 1.7–1.5‐fold reduction activity trypsinlike enzymes during digestion, with 10‐h delay peak activity. Using [1,3‐ 3...