Co-reporter:Ronald J. Nachman
Peptides 2017 Volume 98(Volume 98) pp:
Publication Date(Web):1 December 2017
DOI:10.1016/j.peptides.2017.09.010
Co-reporter:Qirui Zhang;Janusz Zabrocki;David L. Denlinger;Krzysztof Kaczmarek;Ronald J. Nachman
PNAS 2011 Volume 108 (Issue 41 ) pp:16922-16926
Publication Date(Web):2011-10-11
DOI:10.1073/pnas.1113863108
The dormant state known as diapause is widely exploited by insects to circumvent winter and other adverse seasons. For an
insect to survive, feed, and reproduce at the appropriate time of year requires fine coordination of the timing of entry into
and exit from diapause. One of the hormones that regulates diapause in moths is the 24-aa neuropeptide, diapause hormone (DH).
Among members of the Helicoverpa/Heliothis complex of agricultural pests, DH prompts the termination of pupal diapause. Based on the structure of DH, we designed several
agonists that are much more active than DH in breaking diapause. One such agonist that we describe also prevents the entry
into pupal diapause when administered to larvae that are environmentally programmed for diapause. In addition, we used the
unique antagonist development strategy of incorporating a dihydroimidazole (“Jones”) trans-Proline mimetic motif into one of our DH agonists, thereby converting the agonist into a DH antagonist that blocks the termination
of diapause. These results suggest potential for using such agents or next-generation derivatives for derailing the success
of overwintering in pest species.
Co-reporter:Susanne Neupert, William K. Russell, Reinhard Predel, David H. Russell, Otto F. Strey, Pete D. Teel, Ronald J. Nachman
Journal of Proteomics 2009 Volume 72(Issue 6) pp:1040-1045
Publication Date(Web):20 August 2009
DOI:10.1016/j.jprot.2009.06.007
Ticks (Ixodoidea) likely transmit the greatest variety of human and animal pathogens of any arthropod vector. Despite their medical significance little data is available about the messenger molecules in the central nervous system that coordinate all physiological processes in these animals, including behaviour. In our study, we performed the first comprehensive neuropeptidomic analysis of a tick species by using MALDI-TOF mass spectrometry. Specifically we analyzed the neuropeptides in the synganglion of Ixodes scapularis. The forthcoming sequence of the genome of this species will represent the first genomic analysis of a member of the large subphylum Chelicerata. For our approach we used information from predicted neuropeptide precursor sequences found in EST databases [Christie, AE. Neuropeptide discovery in Ixodoidea: an in silico investigation using publicly accessible expressed sequence tags. Gen Comp Endocrinol 2008;157:174–185] as well as data obtained by complete de novo sequencing. The direct tissue profiling yielded 20 neuropeptides from 12 neuropeptide precursors. The sequences of these neuropeptides are not as unique as predicted; a comparison with the peptidome of other invertebrates shows a close relationship with insect neuropeptides. This work will provide a resource for studying tick neurobiology and will hopefully also help to identify novel targets for tick and tick-borne disease control.
Co-reporter:Ronald J. Nachman, Young-Joon Kim, Xiaodong J. Wang, Felicia A. Etzkorn, Krzysztof Kaczmarek, Janusz Zabrocki, Michael E. Adams
Bioorganic & Medicinal Chemistry 2009 Volume 17(Issue 12) pp:4216-4220
Publication Date(Web):15 June 2009
DOI:10.1016/j.bmc.2009.03.036
The pyrokinin/pheromone biosynthesis activating neuropeptide (PK/PBAN) family plays a multifunctional role in an array of important physiological processes in insects, including regulation of sex pheromone biosynthesis in moths. A cyclic PK/PBAN analog (cyclo[NTSFTPRL]) retains significant activity on the pheromonotropic HevPBANR receptor from the tobacco budworm Heliothis virescens expressed in CHO-K1 cells. Previous studies indicate that this rigid, cyclic analog adopts a type I β-turn with a transPro over residues TPRL within the core PK/PBAN region. An analog containing an (E)-alkene, trans-Pro mimetic motif was synthesized, and upon evaluation on the HevPBANR receptor found to have an EC50 value that is not statistically different from a parent C-terminal PK/PBAN hexapeptide sequence. The results, in aggregate, provide strong evidence for the orientation of Pro and the core conformation of PK/PBAN neuropeptides during interaction with the expressed PBAN receptor. The work further identifies a novel scaffold with which to design mimetic PBAN analogs as potential leads in the development of environmentally favorable pest management agents capable of disrupting PK/PBAN-regulated pheromone signaling systems.
Co-reporter:Suparna Taneja-Bageshwar;Allison Strey;Pawel Zubrzak;Patricia V. Pietrantonio;Ronald J. Nachman
Archives of Insect Biochemistry and Physiology 2006 Volume 62(Issue 3) pp:
Publication Date(Web):16 JUN 2006
DOI:10.1002/arch.20129
The systematic analysis of structure-activity relationships of insect kinins on two heterologous receptor-expressing systems is described. Previously, kinin receptors from the southern cattle tick, Boophilus microplus (Canestrini) [Holmes et al., Insect Mol Biol 9:457–465 (2000); Holmes et al., Insect Mol Biol 12:27–38 (2003)], and the dengue vector, the mosquito Aedes aegypti (L.) [Pietrantonio et al., Insect Mol Biol 14:55–67 (2005)], were functionally and stably expressed in CHO-K1 cells. In order to determine which kinin residues are critical for the peptide-receptor interaction, kinin core analogs were synthesized as an Ala-replacement series of the peptide FFSWGa and tested by a calcium bioluminescence plate assay. The amino acids Phe1 and Trp4 were essential for activity of the insect kinins in both receptors. It was confirmed that the pentapeptide kinin core is the minimum sequence required for activity and that the C-terminal amide is also essential. In contrast to the tick receptor, a large increase in efficacy is observed in the mosquito receptor when the C-terminal pentapeptide is N-terminally extended to a hexapeptide. The aminoisobutyric acid (Aib)-containing analog, FF[Aib]WGa, was as active as superagonist FFFSWGa on the mosquito receptor in contrast to the tick receptor where it was statistically more active than FFFSWGa by an order of magnitude. This restricted conformation Aib analog provides information on the conformation associated with the interaction of the insect kinins with these two receptors. Furthermore, the analog FF[Aib]WGa has been previously shown to resist degradation by the peptidases ACE and nephrilysin and represents an important lead in the development of biostable insect kinin analogs that ticks and mosquitoes cannot readily deactivate. Arch Insect Biochem Physiol 62:128–140, 2006. Published 2006 Wiley-Liss, Inc.
Co-reporter:Ronald J. Nachman;Krzysztof Kaczmarek;Howard J. Williams;Geoffrey M. Coast;Janusz Zabrocki
Biopolymers 2004 Volume 75(Issue 5) pp:
Publication Date(Web):29 SEP 2004
DOI:10.1002/bip.20155
The insect kinins are potent diuretic peptides that preferentially form a cis-Pro, type VI β-turn. An insect kinin analog containing (2S,4S)-4-aminopyroglutamate, a novel cis-peptide bond, type VI β-turn motif, demonstrates significant activity in the physiological range in a cricket diuretic assay. This is the first instance of a 4-aminopyroglutamate analog of a peptide with a preference for a type VI turn that demonstrates significant bioactivity. The results provide further confirmatory evidence for the active conformation of the insect kinins, and a new scaffold with which to design biostable, peptidomimetic analogs capable of disrupting critical insect kinin-regulated processes in insects. © 2004 Wiley Periodicals, Inc. Biopolymers, 2004
Co-reporter:Ronald J. Nachman
Peptides (March 2014) Volume 53() pp:1-2
Publication Date(Web):1 March 2014
DOI:10.1016/j.peptides.2014.03.002
Co-reporter:Reinhard Predel, Susanne Neupert, William K. Russell, Frank Hauser, David H. Russell, Andrew Li, Ronald J. Nachman
Peptides (March 2013) Volume 41() pp:2-7
Publication Date(Web):1 March 2013
DOI:10.1016/j.peptides.2012.12.009
Sandflies (Phlebotominae, Nematocera, Diptera) are responsible for transmission of leishmaniasis and other protozoan-borne diseases in humans, and these insects depend on the regulation of water balance to cope with the sudden and enormous intake of blood over a very short time period. The sandfly inventory of neuropeptides, including those that regulate diuretic processes, is completely unknown. Direct MALDI-TOF/TOF mass spectrometric analysis of dissected ganglia of Phlebotomus papatasi, combined with a data-mining of sandfly genome ‘contigs’, was used to identify native CAPA-peptides, a peptide class associated with the regulation of diuresis in other hematophagous insects. The CAPA-peptides identified in this study include two CAPA-PVKs, differentially processed CAPA-PK, and an additional CAPA precursor peptide. The mass spectrometric analysis of different parts of the neuroendocrine system of the sandfly indicate that it represents the first insect which accumulates CAPA-PVKs exclusively in hormone release sites of abdominal ganglia and CAPA-PK (nearly) exclusively in the corpora cardiaca. Additionally, sandflies feature the smallest abdominal ganglia (∼35 μm) where CAPA-peptides could be detected so far. The small size of the abdominal ganglia does not appear to affect the development of the median neurosecretory system as it obviously does in another comparably small insect species, Nasonia vitripennis, in which no capa-gene expression was found. Rather, immunocytochemical analyses confirm that the general architecture in sandflies appears identical to that of much larger mosquitoes.Highlights► Sandflies are responsible for transmission of leishmaniasis and other protozoan-borne diseases in humans. ► To cope with large intake of blood meal, sandflies depend on precise regulation of water balance. ► First peptides from the tiny disease vector were identified via mass spectrometric analysis. ► CAPA-gene peptides identified are associated with diuresis in other blood-feeding insects. ► First insects which accumulate CAPA-PVKs exclusively in hormone release sites of abdominal ganglia and CAPA-PK in the corpora cardiaca.
Co-reporter:Ronald J. Nachman
Peptides (March 2013) Volume 41() pp:1
Publication Date(Web):1 March 2013
DOI:10.1016/j.peptides.2013.03.016
Co-reporter:Ronald J. Nachman, Xiaodong J. Wang, Felicia A. Etzkorn, Krzysztof Kaczmarek, Janusz Zabrocki, Juan Lopez, Geoffrey M. Coast
Peptides (March 2013) Volume 41() pp:101-106
Publication Date(Web):1 March 2013
DOI:10.1016/j.peptides.2012.09.026
The CAP2b neuropeptide family plays an important role in the regulation of the processes of diuresis and/or antidiuresis in a variety of insects. While Manse-CAP2b (pELYAFPRV-NH2) and native CAP2bs elicit diuretic activity in a number of species of flies, native CAP2b sequences have been shown to elicit antidiuretic activity in the kissing bug Rhodnius prolixus and the green stink bug Acrosternum hilare, the latter being an important pest of cotton and soybean in the southern United States. Analogs of CAP2b containing either a (Z)-alkene, cis-Pro or an (E)-alkene, trans-Pro isosteric component were synthesized and evaluated in an in vitro stink bug diuretic assay, which involved measurement of fluid secretion by Malpighian tubules isolated from A. hilare. The conformationally constrained trans-Pro analog demonstrated statistically significant antidiuretic activity, whereas the cis-Pro analog failed to elicit activity. The results are consistent with the adoption of a trans orientation for the Pro in CAP2b neuropeptides during interaction with receptors associated with the antidiuretic process in the stink bug. In addition, the results are further consistent with a theory of ligand-receptor coevolution between the CAP2b and pyrokinin/PBAN neuropeptide classes, both members of the ‘-PRXamide’ superfamily. This work further identifies a scaffold with which to design mimetic CAP2b analogs as potential leads in the development of environmentally favorable pest management agents capable of disrupting CAP2b-regulated diuretic/antidiuretic functions.Highlights► CAP2b analogs were synthesized with (Z)-alkene, and (E)-alkene components. ► These components lock in a cis- or trans-Proline orientation, respectively. ► They were tested for antidiuretic activity on stink bug Malpighian tubules. ► Only the trans-Pro analog had antidiuretic activity. ► This is consistent with the Pro in CAP2b adopting a trans orientation.
Co-reporter:Ronald J. Nachman, Krzysztof Kaczmarek, Janusz Zabrocki, Geoffrey M. Coast
Peptides (March 2012) Volume 34(Issue 1) pp:262-265
Publication Date(Web):1 March 2012
DOI:10.1016/j.peptides.2011.09.021
The multifunctional ‘insect kinins’ of arthropods share the evolutionarily conserved C-terminal pentapeptide core sequence Phe-X1-X2-Trp-Gly-NH2, where X1 = His, Asn, Ser, or Tyr and X2 = Ser, Pro, or Ala. Insect kinins regulate diuresis in many species of insects, including the house cricket, Acheta domesticus. Insect kinins, however, are susceptible to fast enzymatic degradation by endogenous peptidases that severely limit their potential use as tools for pest control or for endocrinological studies. To enhance resistance to peptidases, the core insect kinin sequence was structurally modified in this study to replace native peptide bonds susceptible to proteolytic degradation. These modifications include incorporation of two stereochemical variants of the β-turn mimetic motif 4-aminogutamate in place of the X1-X2 residues, insertion of a reduced peptide bond between residues Trp-Gly, and replacement of the Phe residue with a hydrocinnamyl group. The resulting biostable, peptidomimetic analogs contain no native peptide bonds and yet retain significant diuretic activity in an in vitro cricket Malpighian tubule fluid secretion assay, matching the efficacy of a native A. domesticus kinin (Achdo-KI). These novel analogs represent ideal new tools for endocrinologists studying arthropod kinin regulated processes in vivo, and provide leads in the development of novel, environmentally friendly pest insect management agents capable of disruption of the critical processes that kinins regulate.Highlights► Two biostable, peptidomimetic analogs of insect kinin neuropeptides were synthesized that contain no native peptide bonds. ► These analogs match the efficacy of a native insect kinin in an in vitro cricket diuretic assay, although they are less potent. ► The simplified mimetic insect kinin analogs represent a significant step toward the development of completely non-peptide analogs.
Co-reporter:Ronald J. Nachman
Peptides (March 2012) Volume 34(Issue 1) pp:1-2
Publication Date(Web):1 March 2012
DOI:10.1016/j.peptides.2012.01.021
Co-reporter:Reinhard Predel, William K. Russell, David H. Russell, Charles P.-C. Suh, Ronald J. Nachman
Peptides (March 2012) Volume 34(Issue 1) pp:39-43
Publication Date(Web):1 March 2012
DOI:10.1016/j.peptides.2011.10.008
The cotton fleahopper, Pseudatomoscelis seriatus (Reuter), is an economically important pest of cotton, and increasing concerns over resistance, detrimental effects on beneficial insects and safety issues associated with traditional insecticide applications have led to an interest in research on novel, alternative strategies for control. One such approach requires a more basic understanding of the neurohormonal system that regulates important physiological properties of the fleahopper; e.g. the expression of specific messenger molecules such as neuropeptides. Therefore we performed a peptidomic study of neural tissues from the fleahopper which led to the first identification of the sequences of native peptide hormones. These peptide hormones include the following neuropeptides: corazonin, short neuropeptide F (sNPF), myosuppressin, CAPA-pyrokinin and CAPA-PVK peptides. The CAPA-pyrokinin, sNPF, and CAPA-PVK peptides represent novel sequences. A comparison of fleahopper neuropeptides with those of related heteropteran species indicates that they are quite different. The sNPF of P. seriatus shows, among others, a novel substitution of Leu with Phe within the C-terminal region; a modification that sets it apart from the known sNPFs of not only other Heteroptera but of other arthropod species as well. The identity of the neuropeptides native to the fleahopper can aid in the potential development of biostable, bioavailable mimetic agonists and antagonists capable of disrupting the physiological functions that these neuropeptides regulate.Highlights► Fleahoppers belong to the most destructive insect pests of cotton in the US. ► Concerns over human safety and the disruptive nature of insecticides exist. ► Alternate means of control necessitate knowledge of the basic physiological properties. ► We identified by mass spectrometry fleahopper-specific peptide hormones. ► Findings may help developing mimetica capable of disrupting physiological functions.
Co-reporter:Ronald J. Nachman, Mohamad Hamshou, Krzysztof Kaczmarek, Janusz Zabrocki, Guy Smagghe
Peptides (March 2012) Volume 34(Issue 1) pp:266-273
Publication Date(Web):1 March 2012
DOI:10.1016/j.peptides.2011.11.009
The pyrokinins (PK) are multifunctional neuropeptides found in a variety of arthropod species, including the pea aphid Acyrthosiphon pisum (Hemiptera: Aphidae). A series of biostable pyrokinin analogs based on the shared C-terminal pentapeptide core region were fed in solutions of artificial diet to the pea aphid over a period of three days and evaluated for antifeedant and aphicidal activity. The analogs contained either modified Pro residues Oic or Hyp and or a d-amino acid in key positions to enhance resistance to tissue-bound peptidases and retain activity in a number of PK bioassays. A series of PK analogs conjugated with two lengths of polyethyleneglycol (PEG) polymers were also evaluated in the aphid feeding assay. Three of the biostable PK analogs demonstrated potent antifeedant activity, with a marked reduction in honeydew formation and very high mortality after 1 day. In contrast, a number of unmodified, natural pyrokinins and several other analogs containing some of the same structural components that promote biostability were inactive. Two of the most active analogs, Oic analog PK-Oic-1 (FT[Oic]RL-NH2) and PEGylated analog PK-dF-PEG8 [(P8)-YF[dF]PRL-NH2], featured aphicidal activity calculated at LC50's of 0.042 nmol/μl [0.029 μg/μl] (LT50 of 1.0 day) and 0.126 nmol/μl (LT50 of 1.3 days), respectively, matching the potency of some commercially available aphicides. Notably, a PEGylated analog of a PK antagonist can block over 55% of the aphicidal effects of the potent PK agonist PK-Oic-1, suggesting that the aphicidal effects are mediated by a PK receptor. The mechanism of this activity has yet to be established, though the aphicidal activity of the biostable analogs may result from disruption of digestive processes by interfering with gut motility patterns, a process shown to be regulated by the PKs in other insects. The active PK analogs represent potential leads in the development of selective, environmentally friendly aphid pest control agents.Highlights► Biostable insect pyrokinin analogs with Oic show potent oral antifeedant and aphicidal activity. ► A PEG-polymer conjugated pyrokinin analog shows potent oral antifeedant and aphicidal activity. ► Unmodified, native aphid pyrokinins are inactive. ► Aphicidal activity is blocked by a PK antagonist, suggesting activity is mediated by a PK receptor. ► The pyrokinin analogs represent leads in the development of novel aphid pest control agents.
Co-reporter:Ronald J. Nachman, Kamran Mahdian, Dick R. Nässel, R. Elwyn Isaac, Nan Pryor, Guy Smagghe
Peptides (March 2011) Volume 32(Issue 3) pp:587-594
Publication Date(Web):1 March 2011
DOI:10.1016/j.peptides.2010.09.013
The tachykinin-related peptides (TRPs) are multifunctional neuropeptides found in a variety of arthropod species, including the pea aphid Acyrthosiphon pisum (Hemiptera: Aphidae). Two new biostable TRP analogs containing multiple, sterically hindered Aib residues were synthesized and found to exhibit significantly enhanced resistance to hydrolysis by angiotensin converting enzyme and neprilysin, membrane-bound enzymes that degrade and inactivate natural TRPs. The two biostable analogs were also found to retain significant myostimulatory activity in an isolated cockroach hindgut preparation, the bioassay used to isolate and identify the first members of the TRP family. Indeed one of the analogs (Leuma-TRP-Aib-1) matched the potency and efficacy of the natural, parent TRP peptide in this myotropic bioassay. The two biostable TRP analogs were further fed in solutions of artificial diet to the pea aphid over a period of 3 days and evaluated for antifeedant and aphicidal activity and compared with the effect of treatment with three natural, unmodified TRPs. The two biostable multi-Aib TRP analogs were observed to elicit aphicidal effects within the first 24 h. In contrast natural, unmodified TRPs, including two that are native to the pea aphid, demonstrated little or no activity. The most active analog, double-Aib analog Leuma-TRP-Aib-1 (pEA[Aib]SGFL[Aib]VR-NH2), featured aphicidal activity calculated at an LC50 of 0.0083 nmol/μl (0.0087 μg/μl) and an LT50 of 1.4 days, matching or exceeding the potency of commercially available aphicides. The mechanism of this activity has yet to be established. The aphicidal activity of the biostable TRP analogs may result from disruption of digestive processes by interfering with gut motility patterns and/or with fluid cycling in the gut; processes shown to be regulated by the TRPs in other insects. These active TRP analogs and/or second generation analogs offer potential as environmentally friendly pest aphid control agents.
Co-reporter:Ronald J. Nachman
Peptides (March 2011) Volume 32(Issue 3) pp:433
Publication Date(Web):1 March 2011
DOI:10.1016/j.peptides.2010.12.008
Co-reporter:Guy Smagghe, Kamran Mahdian, Pawel Zubrzak, Ronald J. Nachman
Peptides (March 2010) Volume 31(Issue 3) pp:498-505
Publication Date(Web):1 March 2010
DOI:10.1016/j.peptides.2009.07.001
The insect kinins are multifunctional neuropeptides found in a variety of arthropod species, including the pea aphid Acyrthosiphon pisum (Hemiptera: Aphidae). A series of biostable insect kinin analogs based on the shared C-terminal pentapeptide core region were fed in solutions of artificial diet to the pea aphid over a period of 3 days and evaluated for antifeedant and aphicidal activity. The analogs contained either α,α-disubstituted or β-amino acids in key positions to enhance resistance to tissue-bound peptidases and retain activity in a number of insect kinin bioassays and/or on expressed receptors. Three of the biostable analogs demonstrated antifeedant activity, with a marked reduction in honeydew formation observed after 1 day, and very high mortality. In contrast, an unmodified, parent insect kinin and two other analogs containing some of the same structural components that promote biostability are inactive. The most active analog, double Aib analog K-Aib-1 ([Aib]FF[Aib]WGa), featured aphicidal activity calculated at an LC50 of 0.063 nmol/μl (0.048 μg/μl) and an LT50 of 1.68 days, matching the potency of some commercially available aphicides. The mechanism of this activity has yet to be established. The aphicidal activity of the biostable insect kinin analogs may result from different potential mechanisms as disruption of digestive processes by interfering with gut motility patterns, digestive enzyme release, and/or with fluid cycling in the gut, and also nutrient transport across the gut itself; all processes shown to be regulated by the insect kinins in other insects. However the mechanism(s) is(are) not yet known. The active insect kinin analogs represent potential leads in the development of selective, environmentally friendly pest aphid control agents.
Co-reporter:Ronald J. Nachman
Peptides (March 2010) Volume 31(Issue 3) pp:371
Publication Date(Web):1 March 2010
DOI:10.1016/j.peptides.2010.01.014
Co-reporter:Ronald J. Nachman
Peptides (June 2015) Volume 68() pp:1-2
Publication Date(Web):1 June 2015
DOI:10.1016/j.peptides.2015.04.005
