| 1. |
- Bungart, D, et al.
(författare)
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Occurrence of analogues of the myotropic neuropeptide orcokinin in the shore crab, Carcinus maenas : evidence for a novel neuropeptide family.
- 1995
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Ingår i: Peptides. - 0196-9781 .- 1873-5169. ; 16:1, s. 67-72
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Tidskriftsartikel (refereegranskat)abstract
- By use of an enzyme immunoassay that was developed for the determination of orcokinin, a myotropic neuropeptide of the sequence NFDEIDRSGFGFN from the crayfish, Orconectes limosus, immunoreactive material was detected in extracts of thoracic ganglia from the shore crab, Carcinus maenas. Isolation of the immunoreactive material was achieved by the following steps: 1) prepurification by gel filtration, 2) immunoaffinity chromatography on an anti-orcokinin IgG protein-A sepharose column, and 3) reversed-phase HPLC. The HPLC profile after affinity purification revealed three main immunoreactive peptides that were rechromatographed. None of these peptides was identical to orcokinin in terms of retention time. Automated gas-phase sequencing revealed these peptides to be analogues of orcokinin differing in one amino acid residue. They were named [Ser9]-, [Ala13]- and [Val13]orcokinin (NFDEIDRSSFGFN, Mr 1549.3; NFDEIDRSGFGFA, Mr 1475.3; NFDEIDRSGFGFV, Mr 1503.9). Carboxypeptidase A treatment of the peptides indicated a free C-terminus. Complete characterization of the three peptides was achieved from approximately 230 thoracic ganglia of Carcinus maenas.
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| 2. |
- Dircksen, Heinrich, 1954-, et al.
(författare)
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Structure, distribution, and biological activity of novel members of the allatostatin family in the crayfish Orconectes limosus.
- 1999
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Ingår i: Peptides. - 0196-9781 .- 1873-5169. ; 20:6, s. 695-712
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Tidskriftsartikel (refereegranskat)abstract
- In the central and peripheral nervous system of the crayfish, Orconectes limosus, neuropeptides immunoreactive to an antiserum against allatostatin I (= Dipstatin 7) of the cockroach Diploptera punctata have been detected by immunocytochemistry and a sensitive enzyme immunoassay. Abundant immunoreactivity occurs throughout the central nervous system in distinct interneurons and neurosecretory cells. The latter have terminals in well-known neurohemal organs, such as the sinus gland, the pericardial organs, and the perineural sheath of the ventral nerve cord. Nervous tissue extracts were separated by reverse-phase high-performance liquid chromatography and fractions were monitored in the enzyme immunoassay. Three of several immunopositive fractions have been purified and identified by mass spectroscopy and microsequencing as AGPYAFGL-NH2, SAGPYAFGL-NH2, and PRVYGFGL-NH2. The first peptide is identical to carcinustatin 8 previously identified in the crab Carcinus maenas. The others are novel and are designated orcostatin I and orcostatin II, respectively. All three peptides exert dramatic inhibitory effects on contractions of the crayfish hindgut. Carcinustatin 8 also inhibits induced contractions of the cockroach hindgut. Furthermore, this peptide reduces the cycle frequency of the pyloric rhythms generated by the stomatogastric nervous system of two decapod species in vitro. These crayfish allatostatin-like peptides are the first native crustacean peptides with demonstrated inhibitory actions on hindgut muscles and the pyloric rhythm of the stomatogastric ganglion.
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| 3. |
- Stangier, Joachim, et al.
(författare)
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Distribution of a novel cardioactive neuropeptide (CCAP) in the nervous system of the shore crab Carcinus maenas
- 1988
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Ingår i: Peptides. - : Elsevier. - 0196-9781 .- 1873-5169. ; 9:4, s. 795-800
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Tidskriftsartikel (refereegranskat)abstract
- A radioimmunoassay (RIA) for the recently discovered crustacean cardioactive peptide (CCAP) has been developed and used to determine contents of CCAP in different parts of the nervous system of the shore crab Carcinus maenas. Immunoreactive material was detected throughout the nervous system. In contrast to the main ganglia which contained low levels of approximately 1.4 pmol CCAP/mg protein (brain and thoracic ganglion), a high concentration was found in a neurohemal structure, the pericardial organs (PO) (868 pmol/mg protein). A predominantly neurohormonal role of CCAP thus suggested is further supported by in vitro release studies. Incubation of POs in high (K+) saline showed that CCAP is secretable in considerable amounts by a Ca++-dependent release mechanism.
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| 4. |
- Stangier, J, et al.
(författare)
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Identification and immunocytochemical localization of proctolin in pericardial organs of the shore crab, Carcinus maenas.
- 1986
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Ingår i: Peptides. - : Elsevier. - 0196-9781 .- 1873-5169. ; 7:1, s. 67-72
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Tidskriftsartikel (refereegranskat)abstract
- The occurrence of proctolin (Arg-Tyr-Leu-Pro-Thr) in crab neurohemal pericardial organs (POs) has been demonstrated by isolation of the pentapeptide by HPLC and manual microsequencing according to the DABITC-PITC double coupling technique. From one pair of POs approximately 5.4 pmol were obtained (= 45 pmol/mg protein). Immunocytochemically, an extensive system of positive structures was found in both whole mount preparations and semithin sections, consisting of numerous varicose fibres of varying diameter and many knoblike neurosecretory terminals abutting upon the epineurium of the PO trunks. The relatively high concentration in the POs as well as the pattern of proctolin-positive fibres and terminals clearly suggest a neurohormonal role of the pentapeptide in decapod crustaceans.
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