Isolation and structural determination of three peptides from the insect Locusta migratoria. Identification of a deoxyhexose-linked peptide (original) (raw)
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Insect Biochemistry and Molecular Biology, 2000
Eighteen peptides were isolated from brain extracts of the stick insect Carausius morosus. The peptides were purified in four steps by high-performance liquid chromatography, monitored by their ability to inhibit juvenile hormone biosynthesis by corpora allata of the cricket Gryllus bimaculatus in vitro, and chemically characterised by Edman degradation and mass spectrometry. We obtained complete primary-structure information for nine peptides, four of which belong to the peptide family characterised by a common C-terminal pentapeptide sequence-YXFGLamide. The remaining five belong to the W 2 W 9 amide peptide family, nonapeptides characterised by having the amino acid tryptophan in positions 2 and 9. The amino-acid sequence of two other peptides could not be completely resolved by means of Edman degradation; however, these peptides could be allocated to the-YXFGLamide and the W 2 W 9 amide family, respectively, by comparison of retention times, co-elution and mass spectrometry. Both classes of neuropeptides strongly inhibit juvenile hormone biosynthesis in crickets but show no inhibiting effect on the corpora allata of the stick insect.
Allatoregulatory peptides in Lepidoptera, structures, distribution and functions
Journal of Insect Physiology, 2008
Allatoregulatory peptides either inhibit (allatostatins) or stimulate (allatotropins) juvenile hormone (JH) synthesis by the corpora allata (CA) of insects. However, these peptides are pleitropic, the regulation of JH biosynthesis is not their only function. There are currently three allatostatin families (A-, Band nd C-type allatostatins) that inhibit JH biosynthesis, and two structurally unrelated allatotropins. The C-type allatostatin, characterised by its blocked N-terminus and a disulphide bridge between its two cysteine residues, was originally isolated from Manduca sexta. This peptide exists only in a single from in Lepidoptera and is the only peptide that has been shown to inhibit JH synthesis by the CA in vitro in this group of insects. The C-type allatostatin also inhibits spontaneous contractions of the foregut. The A-type allatostatins, which exist in multiple forms in a single insect, have also been characterised from Lepidoptera. This family of peptides does not appear to have any regulatory effect on JH biosynthesis, but does inhibit foregut muscle contractions. Two structurally unrelated allatotropins stimulate JH biosynthesis in Lepidoptera. The first was identified in M. sexta (Manse-AT) and occurs in other moths. The second (Spofr AT2) has only been identified in Spodoptera frugiperda. Manduca sexta allatotropin also stimulates heart muscle contractions and gut peristalsis, and inhibits ion transport across the midgut of larval M. sexta. The C-terminal (amide) pentapeptide of Manse-AT is important for JH biosynthesis activity. The most active conformation of Manse-AS requires the disulphide bridge, although the aromatic residues also have a significant effect on biological activity. Both A-and C-type allatostatins and Manse-AT are localised in neurosecretory cells of the brain and are present in the corpora cardiaca, CA and ventral nerve cord, although variations in localisation exist in different moths and at different stages of development. The presence of Manse-AS and Manse-AT in the CA correlates with the biological activity of these peptides on JH biosynthesis. There is currently no explanation for the presence of A-type allatostatins in the CA. The three peptide types are also co-localised in neurosecretory cells of the frontal ganglion, and are present in the recurrent nerve that supplies the muscles of the gut, particularly the crop and stomodeal valve, in agreement with their role in the regulation of gut peristalsis. There is also evidence that they are expressed in the midgut and reproductive tissues.
European Journal of Biochemistry, 1989
We have isolated two major 6-kDa peptides from extracts of corpora cardiaca of adult females of Locusta migratoria. These peptides have been characterized by peptide sequencing and liquid secondary-ion mass spectrometry. They are structurally related dimers, one (6278.5 Da) being a homodimer (A-A chains), the other (6280.5 Da) being a heterodimer (A-B chains). A 60% similarity exists between the A and B chains. Both peptides have been chemically synthesized and the synthetic compounds appeared to be identical to the native ones. Polyclonal antibodies raised against each of these peptides demonstrated that they were contained within the secretory granules of the intrinsic cells of the glandular lobes of the corpora cardiaca. The physiological significance of these two peptides is unknown but, using the synthetic peptides, we are currently probing their biological role.
Peptides in the Locusts, Locusta migratoria and Schistocerca gregaria
Peptides, 1997
in the locusts, Locusta migratoria and Schistocerca gregaria: A review. PEPTIDES 18(1) [153][154][155] 1997.-The first peptide identified in locusts was adipokinetic hormone I (AKH-I), a neurohormone mobilizing lipids from the fat body. No other locust peptides were isolated until 1985. From then on peptide identification started to boom at such a tremendously fast rate that even specialists in the field could hardly keep track. At this moment the total number of different insect neuropeptide sequences exceeds 100. Currently, the locusts Locusta migratoria and Schistocerca gregaria are the species from which the largest number of neuropeptides has been isolated and sequenced, namely 56. Myotropic bioassays have played a major role in the isolation and subsequent structural characterization of locust neuropeptides. They have been responsible for the discovery of locustamyotropins [4], locustapyrokinins [2], locustatachykinins [5], locustakinin [1], locusta accessory gland myotropins [2], locustasulfakinin [1], cardioactive peptide [1], and locustamyoinhibiting peptides [4]
Endocrine peptides and insect reproduction
Invertebrate Reproduction & Development, 2005
In insects, peptide hormones regulate many physiological and developmental processes such as growth, moulting, metamorphosis, reproduction, diapause, feeding and metabolism. This review focuses on those involved in reproduction, in particular vitellogenesis and oogenesis, spermatogenesis, ovulation and pheromone production. Most of these peptides regulate the production of the true gonadotrophic hormones (as in the case of allatostatins, allatotropins and ovary ecdysteroidogenic hormones) or the production of pheromones (as in the case of pheromone biosynthesis activating neuropeptides). Other peptides seem related to reproductive processes, but it is not clear whether they play a true regulatory role. Cloning approaches have greatly facilitated the solution of structural aspects of peptide research; the major challenge now is to approach the functional aspects.
FEATURES OF THE INSECTS NEUROPEPTIDES BIOSYNTHESIS
Ecobiotech, 2018
Ильясов Р.А., Хан Г.Ю., Сонг Д.Х., Лим С.Х., Квон Х.В. Особенности биосинтеза нейропептидов насекомых. Экобиотех, 2018, Т. 1, № 1, С. 52-62. DOI: 10.31163/2618-964X-2018-1-1-52-61. Ilyasov R.A., Han G.Y., Song J.H., Lim S.H., Kwon H.W. Features of the insects neuropeptides biosynthesis. Ecobiotech, 2018, V. 1, No. 1, P. 52-62. DOI: 10.31163/2618-964X-2018-1-1-52-61. Аннотация В статье рассмотрены современные данные о классификации, строении, функциях и распространении нейропептидов у насекомых. Также в статье описываются особенности биосинтеза, процессинга и экспрессии нейропептидов насекомых. Вся доступная современная информация о нейропептидах насекомых и их GPCR (G protein– coupled receptors) рецепторах депонирована в специализированную базу данных нейропептидов насекомых DINeR (Database for Insect Neuropeptide Research). Возможно, что достижения в исследованиях нейропептидов могут быть использованы для создания высокоактивных и экологически безопасных лекарств для полезных насекомых и средств борьбы с насекомыми- вредителями и переносчиками болезней. Abstract In this paper, current data on the classification, structure, functions, and distribution of neuropeptides in insects have reviewed. Also, the article describes the features of biosynthesis, processing and expression of insect neuropeptides. All available up-to-date information on insect neuropeptides and their G protein–coupled receptors (GPCR) deposited into the specialized database of insect neuropeptides DINeR (Database for Insect Neuropeptide Research). Perhaps the advances in of neuropeptide researches can be used to create highly active and ecologically safe drugs for beneficial insects and means of struggle against pest and disease vectors.
The search for new biological activities for selected insect peptides
PESTYCYDY- …, 2008
The search for new biological activities for selected insect peptides ... The search for new biological activities for selected insect peptides ... Mariola KUCZER1, Katarzyna DZIUBASIK1, Mirosław ŁUCZAK2, Anna MAJEWSKA2, Wojciech KAMYSZ3, Alicja SANIEWSKA4 and Danuta ...