Development of a Highly Efficient Long-Acting Cocaine Hydrolase Entity to Accelerate Cocaine Metabolism.

It is particularly challenging to develop a truly effective pharmacotherapy for cocaine use disorder (CUD) treatment. Accelerating cocaine metabolism via hydrolysis at cocaine benzoyl ester using an efficient cocaine hydrolase (CocH) is known as a promising pharmacotherapeutic approach to CUD treatment. Preclinical and clinical studies on our first CocH (CocH1), in its human serum albumin-fused form known as TV-1380, have demonstrated the promise of a general concept of CocH-based pharmacotherapy for CUD treatment. However, the biological half-life of TV-1380 (t1/2 = 8 h in rats, associated with t1/2 = 43-77 h in humans) is not long enough for practical treatment of cocaine dependence, which requires enzyme injection for no more than once weekly. Through protein fusion of a human butyrylcholinesterase mutant (denoted as CocH5) with a mutant (denoted as Fc(M6)) of Fc from human IgG1, we have designed, prepared, and tested a new fusion protein (denoted as CocH5-Fc(M6)) for its pharmacokinetic profile and in vivo catalytic activity against (-)-cocaine. CocH5-Fc(M6) represents the currently most efficient long-acting cocaine hydrolase with both the highest catalytic activity against (-)-cocaine and the longest elimination half-life (t1/2 = 229 ± 5 h) in rats. As a result, even at a single modest dose of 3 mg/kg, CocH5-Fc(M6) can significantly and effectively accelerate the metabolism of cocaine in rats for at least 60 days. In addition, ∼70 nM CocH5-Fc(M6) in plasma was able to completely block the toxicity and physiological effects induced by intraperitoneal injection of a lethal dose of cocaine (60 mg/kg).

Cocaine hydrolase blocks cocaine-induced dopamine transporter trafficking to the plasma membrane.

Cocaine blocks dopamine uptake via dopamine transporter (DAT) on plasma membrane of neuron cells and, as a result, produces the high and induces DAT trafficking to plasma membrane which contributes to the drug seeking or craving. In this study, we first examined the dose dependence of cocaine-induced DAT trafficking and hyperactivity in rats, demonstrating that cocaine at an intraperitoneal dose of 10 mg/kg or higher led to redistribution of most DAT to the plasma membrane while inducing significant hyperactivity in rats. However, administration of 5-mg/kg cocaine (ip) did not significantly induce DAT trafficking or hyperactivity in rats. So the threshold (intraperitoneal) dose of cocaine that can significantly induce DAT trafficking or hyperactivity should be between 5 and 10 mg/kg. These data suggest that when a cocaine dose is high enough to induce significant hyperactivity, it can also significantly induce DAT trafficking to the plasma membrane. Further, the threshold brain cocaine concentration required to induce significant hyperactivity and DAT trafficking was estimated to be ~2.0 ± 0.8 µg/g. Particularly, for treatment of cocaine abuse, previous studies demonstrated that an exogenous cocaine-metabolizing enzyme, for example, CocH3-Fc(M3), can effectively block cocaine-induced hyperactivity. However, it was unknown whether an enzyme could also effectively block cocaine-induced DAT trafficking to the plasma membrane. This study demonstrates, for the first time, that the enzyme is also capable of effectively blocking cocaine from reaching the brain even with a lethal dose of 60-mg/kg cocaine (ip) and, thus, powerfully preventing cocaine-induced physiological effects such as the hyperactivity and DAT trafficking.

Coleopteran-specific StaufenC functions like Drosophila melanogaster Loquacious-PD in dsRNA processing.

In Drosophila melanogaster, PD isoform of the double-stranded RNA binding protein (dsRBP) Loquacious (Loqs-PD) facilitates dsRNA cleavage to siRNA by Dicer-2. StaufenC (StauC) was discovered as a coleopteran-specific dsRBP required for dsRNA processing in coleopteran insects. Here, we show that StauC is essential for the high RNAi efficiency observed in coleopterans. Knockdown of StauC but not the homologs of Loqs-PD and R2D2 evoked a long-lasting insensitivity to RNAi in the coleopteran cell line, Ledp-SL1. The dsRNA insensitivity induced by StauC knockdown could not be overcome merely by an increase in dose or time of exposure to dsRNA or expression of Loquacious or R2D2. Furthermore, StauC but not Loqs and R2D2 are required for processing of dsRNA into siRNA. StauC overexpression also partly restored the impaired RNAi caused by the knockdown of Loqs-PD in D. melanogaster Kc cells. However, StauC was unable to compensate for the loss-of-the function of Dcr-2 or R2D2. Overall, these data suggest that StauC functions like Lops-PD in processing dsRNA to siRNA.

Ternary Polypeptide Nanoparticles with Improved Encapsulation, Sustained Release, and Enhanced In Vitro Efficacy of Carfilzomib.

PURPOSE: To develop a new nanoparticle formulation for a proteasome inhibitor Carfilzomib (CFZ) to improve its stability and efficacy for future in vivo applications. METHODS: CFZ-loaded ternary polypeptide nanoparticles (CFZ/tPNPs) were prepared by using heptakis(6-amino-6-deoxy)-ß-cyclodextrin(hepta-hydrochloride) (HaßCD) and azido-poly(ethylene glycol)-block-poly(L-glutamic acid sodium salt) (N3-PEG-PLE). The process involved ternary (hydrophobic/ionic/supramolecular) interactions in three steps: 1) CFZ was entrapped in the cavity of HaßCD by hydrophobic interaction, 2) the drug-cyclodextrin inclusion complexes were mixed with N3-PEG-PLE to form polyion complex nanoparticles, and 3) the nanoparticles were modified with fluorescent dyes (AFDye 647) for imaging and/or epithelial cell adhesion molecule (EpCAM) antibodies for cancer cell targeting. CFZ/tPNPs were characterized for particle size, surface charge, drug release, stability, intracellular uptake, proteasome inhibition, and in vitro cytotoxicity. RESULTS: tPNPs maintained an average particle size of 50 nm after CFZ entrapment, EpCAM conjugation, and freeze drying. tPNPs achieved high aqueous solubility of CFZ (>1 mg/mL), sustained drug release (t1/2 = 6.46 h), and EpCAM-mediated cell targeting, which resulted in increased intracellular drug accumulation, prolonged proteasome inhibition, and enhanced cytotoxicity of CFZ in drug-resistant DLD-1 colorectal cancer cells. CONCLUSIONS: tPNPs improved stability and efficacy of CFZ in vitro, and these results potentiate effective cancer treatment using CFZ/tPNPs in future vivo studies.

Prevalence, Predictors, and Psychosocial Mechanism of Cancer Information Avoidance: Findings from a National Survey of U.S. Adults.

The current study examined the prevalence, predictors, and psychosocial mechanism of cancer information avoidance (CIA). With a nationally representative sample, we sought to confirm the prevalence of CIA among Americans. Studies, based on crisis decision theory, have shown that a lack of personal or interpersonal resources to manage threat-related information leads to information avoidance. Cancer information overload (CIO) and cancer fatalism are known predictors of CIA, and these factors were viewed as a lack of personal resources. We measured interpersonal resources by an individual's network size. Then, to suggest a psychosocial mechanism of CIA, we tested how those personal resources interacted with interpersonal resources. A two-wave longitudinal survey was conducted using a nationally representative sample of U.S. adults (N = 795 at Wave 1 and 626 at Wave 2). Approximately, 4-5 out of 10 adults had low to high levels of CIA, and they avoided the Internet more than any other source. Items that positively predicted CIA included male gender, being non-Hispanic white, and CIO. Family and personal cancer history negatively predicted CIA. However, the positive relationship between CIO and CIA existed only for people with fewer close friends (i.e., a smaller network size). The lack of personal resources did not lead to CIA for those who had more interpersonal resources that could help them manage threat-related information. The results suggest that social support protects individuals from the emotional stress of cancer information exposure, confirming the buffering model of social support.

PEGylation but Not Fc-Fusion Improves in Vivo Residence Time of a Thermostable Mutant of Bacterial Cocaine Esterase.

It is very popular to fuse a protein drug or drug candidate to the Fc domain of immunoglobulin G (IgG) in order to prolong the in vivo half-life. In this study, we have designed, prepared, and tested an Fc-fused thermostable cocaine esterase (CocE) mutant (known as E196-301, with the T172R/G173Q/L196C/I301C substitutions on CocE) expressed in E. coli. As expected, Fc-fusion does not affect the in vitro enzyme activity and thermal stability of the enzyme and that Fc-E196-301 can favorably bind FcRn with Kd = 386 ± 35 nM. However, Fc-fusion does not prolong the in vivo half-life of E196-301 at all; Fc-E196-301 and E196-301 have essentially the same PK profile (t1/2 = 0.4 ± 0.1 h) in rats. This is the first time demonstrating that Fc-fusion does not prolong in vivo half-life of a protein. This finding is consistent with the mechanistic understanding that E196-301 and Fc-E196-301 are all degraded primarily through rapid proteolysis in the body. The Fc fusion cannot protect E196-301 from the proteolysis in the body. Nevertheless, it has been demonstrated that PEGylation can effectively protect E196-301, as the PEGylated E196-301, i.e., PEG-E196-301, has a significantly prolonged in vivo half-life. It has also been demonstrated that both E196-301 and PEG-E196-301 have dose-dependent in vivo half-lives (e.g., 19.9 ± 6.4 h for the elimination t1/2 of 30 mg/kg PEG-E196-301), as the endogenous proteolytic enzymes responsible for proteolysis of E196-301 (PEGylated or not) are nearly saturated by the high plasma concentration produced by a high dose of E196-301 or PEG-E196-301.

Oligomerization and Catalytic Parameters of Human UDP-Glucuronosyltransferase 1A10: Expression and Characterization of the Recombinant Protein.

UDP-glucuronosyltransferase (UGT), as an integral membrane protein localized in the endoplasmic reticulum, has the ability to detoxify potentially hazardous xenobiotic substances. Most UGTs are expressed in liver, but UGT1A10 has proven to be an extrahepatic enzyme considerably expressed throughout the gastrointestinal tract. Earlier studies indicated that different UGT isoforms could exist in higher-order homo-oligomers or at least dimers within the membrane, but the formation of intermolecular disulfide bridges between UGT molecules was not often observed. In this study, we expressed recombinant human UGT1A10 in human embryonic kidney (HEK)293 and Chinese hamster ovary (CHO) cells to examine its oligomeric states and characterize its enzymatic activities against two therapeutically interesting substrates, morphine and entacapone, including determination of the catalytic rate constant (kcat) values for the first time. It was observed that a majority of the UGT1A10 protein expressed in HEK293 cells existed in covalently crosslinked higher-order oligomers via formation of intermolecular disulfide bonds, whereas formation of the intermolecular disulfide bonds was not observed in the UGT1A10 protein expressed in CHO cells. Owing to the formation of the covalently crosslinked higher-order oligomers, the UGT1A10 protein expressed in HEK293 cells had much lower catalytic activity (particularly the catalytic rate constant kcat) against both morphine and entacapone, compared with the UGT1A10 protein form expressed in CHO cells against the same substrates.

Design, synthesis, and discovery of 5-((1,3-diphenyl-1H-pyrazol-4-yl)methylene)pyrimidine-2,4,6(1H,3H,5H)-triones and related derivatives as novel inhibitors of mPGES-1.

Human mPGES-1 has emerged as a promising target in exploring a next generation of anti-inflammatory drugs, as selective mPGES-1 inhibitors are expected to discriminatively suppress the production of induced PGE2 without blocking the normal biosynthesis of other prostanoids including homeostatic PGE2. Therefore, this therapeutic approach is believed to reduce the adverse effects associated with the application of traditional non-steroidal anti-inflammatory drugs (tNSAIDs) and selective COX-2 inhibitors (coxibs). Identified from structure-based virtue screening, the compound with (Z)-5-benzylidene-2-iminothiazolidin-4-one scaffold was used as lead in rational design of novel inhibitors. Besides, we further designed, synthesized, and evaluated 5-((1,3-diphenyl-1H-pyrazol-4-yl)methylene)pyrimidine-2,4,6(1H,3H,5H)-triones and structurally related derivatives for their in vitro inhibitory activities. According to in vitro activity assays, a number of these compounds were capable of inhibiting human mPGES-1, with the desirable selectivity for mPGES-1 over COX isozymes.

Elucidating the catalytic subunit composition of distinct proteasome subtypes: a crosslinking approach employing bifunctional activity-based probes.

In addition to two well-recognized proteasome subtypes-constitutive proteasomes and immunoproteasomes-mounting evidence also suggests the existence of intermediate proteasome subtypes containing unconventional mixtures of catalytic subunits. Although they appear to play unique biological roles, the lack of practical methods for detecting distinct proteasome subtypes has limited functional investigations. Here, we report the development of activity-based probes that crosslink two catalytic subunits within intact proteasome complexes. Identification of the crosslinked subunit pairs provides direct evidence of the catalytic subunit composition of proteasomes. Using these probes, we found that U266 multiple myeloma cells contain intermediate proteasomes comprising both ß1i and ß2, but not ß1 and ß2i, consistent with previous findings with other cell types. Our bifunctional probes can be utilized in functional investigations of distinct proteasome subtypes in various biological settings.

Selective immunoproteasome inhibitors with non-peptide scaffolds identified from structure-based virtual screening.

As a major component of the crucial nonlysosomal protein degradation pathway in the cells, the proteasome has been implicated in many diseases such as Alzheimer's disease, Huntington's disease, inflammatory bowel diseases, autoimmune diseases, multiple myeloma (MM) and other cancers. There are two main proteasome subtypes: the constitutive proteasome which is expressed in all eukaryotic cells and the immunoproteasome which is expressed in immune cells and can be induced in other cell types. Majority of currently available proteasome inhibitors are peptide backbone-based, having short half-lives in the body. It is highly desirable to identify novel, immunoproteasome-selective inhibitors with non-peptide scaffolds for development of novel therapeutics. Through combined virtual screening and experimental studies targeting the immunoproteasome, we have identified a set of novel immunoproteasome inhibitors with diverse non-peptide scaffolds. Some of the identified inhibitors have significant selectivity for the immunoproteasome over the constitutive proteasome. Unlike most of the currently available proteasome inhibitors, these new inhibitors lacking electrophilic pharmacophores are not expected to form a covalent bond with proteasome after the binding. These non-peptide scaffolds may provide a new platform for future rational drug design and discovery targeting the immunoproteasome.

Understanding the effects of MTV's 16 and Pregnant on adolescent girls' beliefs, attitudes, and behavioral intentions toward teen pregnancy.

This article examines the impact of a popular documentary series about teen pregnancy, MTV's 16 and Pregnant, on adolescent girls' pregnancy-related attitudes, beliefs, and behavioral intentions. The results suggest that girls who watched 16 and Pregnant, compared with a control group, reported a lower perception of their own risk for pregnancy and a greater perception that the benefits of teen pregnancy outweigh the risks. The authors also examined the relationships between homophily and parasocial interaction with the teen moms featured in 16 and Pregnant and attitudes, beliefs, and behavioral intentions, finding that homophily predicted lower risk perceptions, greater acceptance of myths about teen pregnancy, and more favorable attitudes about teen pregnancy. Parasocial interaction demonstrated the same pattern of results, with the addition of also predicting fewer behavioral intentions to avoid teen pregnancy. Last, results revealed that teen girls' perceptions that the message of 16 and Pregnant was encouraging of teen pregnancy predicted homophily and parasocial interaction with the teen moms. Theoretical and practical implications are discussed.

Carfilzomib-Loaded Ternary Polypeptide Nanoparticles Stabilized by Polycationic Complexation.

Carfilzomib (CFZ) is a second-generation proteasome inhibitor showing great efficacy in multiple myeloma treatment, yet its clinical applications for other diseases such as solid cancers are limited due to low aqueous solubility and poor biostability. Ternary polypeptide nanoparticles (tPNPs) are drug carriers that we previously reported to overcome these pharmaceutical limitations by entrapping CFZ in the core of the nanoparticles and protecting the drugs from degradation in biological media. However, preclinical studies revealed that tPNPs would require further improvement in particle stability to suppress initial burst drug release and thus achieve prolonged inhibition of proteasome activity with CFZ against tumor cells in vivo. In this study, CFZ-loaded tPNPs are stabilized by polycations which have varying pKa values and thus differently modulate nanoparticle stability in response to solution pH. Through polyion complexation, the polycations appeared to stabilize the core of tPNPs entrapping CFZ-cyclodextrin inclusion complexes while allowing for uniform particle size before and after freeze drying. Interestingly, CFZ-loaded tPNPs (CFZ/tPNPs) showed pH-dependent drug release kinetics, which accelerated CFZ release as solution acidity increased (pH < 6) without compromising particle stability at the physiological condition (pH 7.4). In vitro cytotoxicity and proteasome activity assays confirmed that tPNPs stabilized with cationic polymers improved bioactivity of CFZ against CFZ-resistant cancer cells, which would be greatly beneficial in combination with pH-dependent drug release for treatment of solid cancers with drug resistance and tumor microenvironment acidosis by using CFZ and other proteasome inhibitors.

A cancer-specific variant of the SLCO1B3 gene encodes a novel human organic anion transporting polypeptide 1B3 (OATP1B3) localized mainly in the cytoplasm of colon and pancreatic cancer cells.

OATP1B3 is a member of the OATP (organic anion transporting polypeptides) superfamily, responsible for mediating the transport of numerous endogenous and xenobiotic substances. Although initially reported to be exclusively expressed in the liver, several studies reported that OATP1B3 is frequently expressed in multiple types of cancers and may be associated with differing clinical outcomes. However, a detailed investigation on the expression and function of OATP1B3 protein in cancer has been lacking. In this study, we confirmed that colon and pancreatic cancer cells express variant forms of OATP1B3, different from OATP1B3 wild-type (WT) expressed in the normal liver. OATP1B3 variant 1 (V1), the most prevalent form among the variants, contains alternative exonic sequences (exon 2a) instead of exons 1 and 2 present in OATP1B3 WT. The translated product of OATP1B3 V1 is almost identical to OATP1B3 WT, with exception to the first 28 amino acids at the N-terminus. Exogenous expression of OATP1B3 V1 revealed that OATP1B3 V1 undergoes post-translational modifications and proteasomal degradation to a differing extent compared to OATP1B3 WT. OATP1B3 V1 showed only modest transport activity toward cholecystokin-8 (CCK-8, a prototype OATP1B3 substrate) in contrast to OATP1B3 WT showing a markedly efficient uptake of CCK-8. Consistent with these results, OATP1B3 V1 was localized mainly in the cytoplasm with a much lower extent of trafficking to the surface membrane compared to OATP1B3 WT. In summary, our results demonstrate that colon and pancreatic cancer cells express variant forms of OATP1B3 with only limited transport activity and different subcellular localization compared to OATP1B3 WT. These observed differences at the molecular and functional levels will be important considerations for further investigations of the biological and clinical significance of OATP1B3 expression in cancer.

Nitric oxide-dependent CYP2B degradation is potentiated by a cytokine-regulated pathway and utilizes the immunoproteasome subunit LMP2.

CYP2B proteins in rat hepatocytes undergo NO-dependent proteolytic degradation, but the mechanisms and the reasons for the specificity towards only certain P450 (cytochrome P450) enzymes are yet unknown. In the present study we found that down-regulation of CYP2B proteins by the NO donor NOC-18 is accelerated by pretreatment of the hepatocytes with IL-1 (interleukin-1ß) in the presence of an NO synthase inhibitor, suggesting that an NO-independent action of IL-1 contributes to the lability of CYP2B proteins. The immunoproteasome subunit LMP2 (large multifunctional peptidase 2) was significantly expressed in hepatocytes under basal conditions, and IL-1 induced LMP2 within 6-12 h of treatment. CYP2B protein degradation in response to IL-1 was attenuated by the selective LMP2 inhibitor UK-101, but not by the LMP7 inhibitor IPSI. The results show that LMP2 contributes to the NO-dependent degradation of CYP2B proteins, and suggest that induction of LMP2 may be involved in the potentiation of this degradation by IL-1.

Activity-based near-infrared fluorescent probe for LMP7: a chemical proteomics tool for the immunoproteasome in living cells.

Probing the unknown: The immunoproteasome, an alternative form of the constitutive proteasome, has been implicated in a number of pathological states such as cancer and autoimmune diseases. In an effort to understand the role of the immunoproteasome in cells, the first immunoproteasome-specific near-infrared fluorescent probe has been developed.

A bright approach to the immunoproteasome: development of LMP2/ß1i-specific imaging probes.

While the constitutive, 26S proteasome plays an important role in regulating many important cellular processes, a variant form known as the immunoproteasome is thought to primarily function in adaptive immune responses. However, recent studies indicate an association of immunoproteasomes with many physiological disorders such as cancer, neurodegenerative, and inflammatory diseases. Despite this, the detailed functions of the immunoproteasome remain poorly understood. Immunoproteasome-specific probes are essential to gain insight into immunoproteasome function. Here, we describe for the first time the development of cell-permeable activity-based fluorescent probes, UK101-Fluor and UK101-B660, which selectively target the catalytically active LMP2/ß1i subunit of the immunoproteasome. These probes facilitate rapid detection of the cellular localization of catalytically active immunoproteasomes in living cells, providing a valuable tool to analyze immunoproteasome functions. Additionally, as LMP2/ß1i may serve as a potential tumor biomarker, an LMP2/ß1i-targeting fluorescent imaging probe may be applicable to a rapid readout assay to determine tumor LMP2/ß1i levels.

Effects of Organic Acids on Drug Release From Ternary Polypeptide Nanoparticles Entrapping Carfilzomib.

Carfilzomib (CFZ) is an FDA-approved proteasome inhibitor with antineoplastic properties against various cancers, yet its short blood retention time after intravenous injection (< 30 min) makes clinical applications limited to multiple myeloma. We previously developed ternary polypeptide nanoparticles (tPNPs) as a new nanoparticle formulation of CFZ to overcome these limitations. The formulation was prepared by polyion complexation between poly(ethylene glycol)-poly(L-glutamate) block copolymers (PEG-PLE) and CFZ-cyclodextrin (CD) inclusion complexes, where CDs were positively charged with 7 primary amines attached while PEG-PLE carried 100 carboxyl groups per polymer chain. Although tPNPs greatly improved biostability of CFZ, CFZ-loaded tPNPs (CFZ-tPNPs) still showed burst drug release and mediocre drug retention under physiological conditions. To address these issues, organic acids are tested as stabilizers in this study to improve particle stability and drug retention for tPNPs. Charge densities in the core of CFZ-tPNPs were optimized with selected organic acids such as citric acid (CA) and lactic acid (LA) at varying mixing ratios. Organic acids successfully maintained small particle size suitable for intravenous injection and drug delivery (diameters < 60 nm), improved CFZ solubility (> 1 mg/mL), allowed for lyophilization and easy reconstitution in various buffers, enhanced drug retention (> 60% post 24 h incubation), and suppressed burst drug release in the first 6 h following solubilization. These results demonstrate that organic acid stabilized tPNPs are useful as an injection formulation of CFZ, which may expand the utility of the proteasome inhibitor.

Gene expression of adipokines and inflammatory cytokines in peripheral blood mononuclear cells of obese dogs.

BACKGROUND: Peripheral blood mononuclear cells (PBMCs) have been identified as a possible marker of inflammation in obesity. Understanding the expression of pro- and anti-inflammatory cytokines in PBMCs in obese dogs will help control obesity-related inflammatory diseases. OBJECTIVES: The aim of this study was to evaluate the role of PBMCs in obesity-associated chronic inflammation by analyzing the expression of adipokines and inflammatory cytokines. METHODS: Blood samples were obtained from 25 subjects and real-time quantitative polymerase chain reaction determinations were performed to quantify the gene expression levels of adipokines and inflammatory cytokines, including TNF-α, IL-17, leptin, MCP-1, and adiponectin, in the PBMCs. RESULTS: The results showed that the gene expression levels of TNF-α (p < 0.001), IL-17 (p < 0.0001), and leptin (p < 0.0001) were strongly upregulated in the PBMCs of obese dogs compared to that in non-obese dogs. CONCLUSIONS: The changes in gene expression levels of inflammation-related adipokines and pro-inflammatory cytokines occur in PBMCs, which may contribute to the low-grade chronic inflammation that is present in obesity.

Identification of juvenile hormone-induced posttranslational modifications of methoprene tolerant and Krüppel homolog 1 in the yellow fever mosquito, Aedes aegypti.

Recent studies reported that JH-regulated phosphorylation status of the JH-receptor complex contributes to its transcription activity in Aedes aegypti. However, phosphorylation sites of these proteins have not yet been identified. In this study, we found that the fusion of an EGFP tag to Ae. aegypti Kr-h1 (AaKr-h1) and Met (AaMet) improved their stability in mosquito Aag-2 cells, which allowed their purification. The liquid chromatography and tandem mass spectrometry analysis of the purified AaKr-h1 showed that the phosphoserine residue at position 694, located in the evolutionarily conserved SVIQ motif, is dephosphorylated when the cells are exposed to JH. The AaKr-h1 dephosphorylation mutant (S694V) showed significantly higher activity in inducing the luciferase gene regulated by JH response elements. The phosphorylation profile of Met also changed after exposing Aag-2 cells to JH III. The Ser-77 and Ser-710 residues of Met were phosphorylated after JH III treatment. In contrast, the two phosphoserine residues at positions 73 and 747 were dephosphorylated after JH III treatment. JH exposure also induced transient and reversible phosphorylation of Thr-664 and Ser-723 residues. Overall, these data show that JH induces changes in post-translational modifications of AaMet and AaKr-h1. SIGNIFICANCE: Female Aedes aegypti mosquitoes are known to vector many disease agents, including Zika virus, dengue virus chikungunya virus, and Mayaro and yellow fever virus. In the present study, we developed an efficient method to prepare Ae. aegypti Met and Kr-h1, which are typically difficult to produce and purify, using a mosquito cell line expression system. A liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based approaches were utilized to map the phosphorylation profiles of the isolated proteins. We then monitored the changes induced by JH activation in the phosphorylation profiles to check if the JH modulates post-translation modification of its key transcription factors. We found that the JH induced alterations in the phosphorylation profiles of the multiple residues of AaMet. In contrast, activation of the JH signaling pathway was accompanied by dephosphorylation of AaKr-h1 at phosphoserine-694, increasing its transcriptional activity. In addition, S694 of AaKr-h1 was located in the RMSSVIQYA motif highly conserved in orthologous proteins from other insect species. These results can help us further understand how JH modulates its key transcription factors and provide a basis for the development of novel insect control strategies.

Systematic Structure-Based Virtual Screening Approach to Antibody Selection and Design of a Humanized Antibody against Multiple Addictive Opioids without Affecting Treatment Agents Naloxone and Naltrexone.

Opioid drug use, especially heroin, is known as a growing national crisis in America. Heroin itself is a prodrug and is converted to the most active metabolite 6-monoacetylmorphine (6-MAM) responsible for the acute toxicity of heroin and then to a relatively less-active metabolite morphine responsible for the long-term toxicity of heroin. Monoclonal antibodies (mAbs) are recognized as a potentially promising therapeutic approach in the treatment of opioid use disorders (OUDs). Due to the intrinsic challenges of discovering an mAb against multiple ligands, here we describe a general, systematic structure-based virtual screening and design approach which has been used to identify a known anti-morphine antibody 9B1 and a humanized antibody h9B1 capable of binding to multiple addictive opioids (including 6-MAM, morphine, heroin, and hydrocodone) without significant binding with currently available OUD treatment agents naloxone, naltrexone, and buprenorphine. The humanized antibody may serve as a promising candidate for the treatment of OUDs. The experimental binding affinities reasonably correlate with the computationally predicted binding free energies. The experimental activity data strongly support the computational predictions, suggesting that the systematic structure-based virtual screening and humanization design protocol is reliable. The general, systematic structure-based virtual screening and design approach will be useful for many other antibody selection and design efforts in the future.