Introduction Directory UMM :Data Elmu:jurnal:I:Insect Biochemistry and Molecular Biology:Vol30.Issue11.Nov2000:

Insect Biochemistry and Molecular Biology 30 2000 1061–1067 www.elsevier.comlocateibmb A third active AKH is present in the pyrgomorphid grasshoppers Phymateus morbillosus and Dictyophorus spumans Karl J. Siegert a, , Roland Kellner b , Gerd Ga¨de a a University of Cape Town, Department of Zoology, Rondebosch 7701, South Africa b Merck KGaA, Biomed FoGBT, D-64271 Darmstadt, Germany Received 7 July 1999; received in revised form 24 March 2000; accepted 30 March 2000 Abstract The corpora cardiaca of the African pyrgomorphid grasshoppers Phymateus morbillosus and Dictyophorus spumans contain three adipokinetic hormones AKHs: besides two already known AKHs, Phm–AKH-I and Scg–AKH-II Ga¨de et al., 1996 [Ga¨de, G., Kellner, R., Rinehart, K.L., 1996. Pyrgomorphid grasshoppers of the genus Phymateus contain species-specific decapeptides of the AKHRPCH family regulating lipid-mobilisation during flight. Physiol. Entomol. 21, 193–202], a new AKH-III, denoted Phm– AKH-III, pGlu–Ile–Asn–Phe–Thr–Pro–Trp–Trp–NH 2 , has been characterised. This is only the second AKH-III identified so far, thus, only three insect species — all of them grasshoppers — contain three active AKHs. Phm–AKH-III differs from Lom–AKH- III from the migratory locust, Locusta migratoria, only in position 2: isoleucine is present instead of leucine. The structure of the Phm–AKH-III was confirmed by synthesis, subsequent mass determination and reversed-phase high-performance liquid chromato- graphy. The synthetic peptide also induced hyperlipaemia in D. spumans and L. migratoria.  2000 Elsevier Science Ltd. All rights reserved. Keywords: Adipokinetic; Hyperlipaemic; Pyrgomorphid; Grasshopper; Locust

1. Introduction

The corpora cardiaca CC of insects synthesise, amongst other peptides, adipokinetic hormones AKHs Hekimi and O’Shea, 1987 which consist of 8–10 amino acids Ga¨de et al., 1997. AKHs induce the activation of enzymes in the fat body, the main AKH target tissue, and as a result haemolymph lipid, carbohydrate andor proline levels change in a number of insect species. Steele 1961 reported increased haemolymph carbohydrate concen- trations hypertrehalosaemic effects after injection of CC extracts into the American cockroach, Periplaneta amer- icana. In the desert locust, Schistocerca gregaria, however, CC extracts induce increased haemolymph lipid concen- trations adipokinetic effectsMayer and Candy, 1969. In certain beetle species AKHs induce increased proline con- centrations hyperprolinaemic effects Ga¨de, 1997a,b. A Corresponding author. Present address: University of Aberdeen, Department of Zoology, Tillydrone Avenue, Aberdeen AB24 2TZ, UK. E-mail address: kjsiegerthotmail.com K.J. Siegert. 0965-174800 - see front matter  2000 Elsevier Science Ltd. All rights reserved. PII: S 0 9 6 5 - 1 7 4 8 0 0 0 0 0 8 1 - 3 peptide from the CC of locusts, now known as Lom–AKH- I, was the first AKH to be fully characterised Stone et al., 1976. Lom–AKH-I became the second member of a fam- ily of invertebrate peptides, the AKHred pigment-concen- trating hormone RPCH family. A second AKH was found in S. gregaria Carlsen et al., 1979 and the migratory locust, Locusta migratoria Ga¨de et al., 1984; these pep- tides were eventually fully characterised Siegert et al., 1985; Ga¨de et al., 1986. P. americana also contains two AKH peptides Scarborough et al., 1984. It is now known that a large number of insect species contain two AKHs whilst others contain only one. The migratory locust, how- ever, is the only insect species known so far to contain three distinct but structurally related active AKHs Table 1. Interestingly, the closely related species S. gregaria seems to lack this third peptide Oudejans et al., 1991. The present study establishes that two African pyrgo- morphid grasshopper species contain a new AKH-III. This finding seems to indicate that energy metabolism in grasshoppers is generally subject to a very sophisticated hormonal control involving three AKHs. 1062 K.J. Siegert et al. Insect Biochemistry and Molecular Biology 30 2000 1061–1067 Table 1 Sequences of relevant AKH peptides including the novel AKH-III isolated in the present study. Molecular masses are given in brackets. Residues identical with those in Phm-AKH-III are given in bold type-face, those similar are italicised, e.g. leucine and isoleucine. The sequencing results of deblocked Phm-3 and Dis-3 are also given Pab-RPCH 929.4 pGlu Leu Asn Phe Ser Pro Gly TrpNH 2 Lom-AKH-I 1158.5 pGlu Leu Asn Phe Thr Pro Asn Trp Gly ThrNH 2 Phm-AKH-I 1144.5 pGlu Leu Asn Phe Thr Pro Asn Trp Gly SerNH 2 Lom-AKH-II 903.4 pGlu Leu Asn Phe Ser Ala Gly TrpNH 2 Scg-AKH-II 933.4 pGlu Leu Asn Phe Ser Thr Gly TrpNH 2 Lom-AKH-III 1072.5 pGlu Leu Asn Phe Thr Pro Trp TrpNH 2 Phm-AKH-III 1072.5 pGlu Ile Asn Phe Thr Pro Trp TrpNH 2 Cycle Residue Phm-3 Dis-3 pmol pmol 1 Ile 44.6l 35.7 2 Asn 44.2 32.9 3 Phe 42.3 31.4 4 Thr 27.2 19.8 5 Pro 19.1 13.8 6 Trp 5.2 4.5 7 Trp 3.4 2.7 8 void — —

2. Materials and methods