« Previous Abstract"Identification and field attraction of the female sex pheromone of a kiwifruit pest, Nokona feralis (Lepidoptera: Sesiidae)"    Next Abstract"Isolation, characterization and bioactivity of a region-specific pheromone, [Val8]sodefrin from the newt Cynops pyrrhogaster" »

Zoolog Sci

Title:		"Evidence for processing enzymes in the abdominal gland of the newt, Cynops pyrrhogaster, that generate sodefrin from its biosynthetic precursor"
Author(s):		Nakada T; Ishizuka Y; Iwata T; Toyoda F; Kato T; Conlon JM; Kikuyama S;
Address:		"Department of Biology, School of Education, Waseda University, Nishiwaseda, Tokyo, Japan"
Journal Title:		Zoolog Sci
Year:		2007
Volume:		24
Issue:		5
Page Number:		521 - 524
DOI:		10.2108/zsj.24.521
ISSN/ISBN:		0289-0003 (Print) 0289-0003 (Linking)
Abstract:		"Sodefrin (Ser-Ile-Pro-Ser-Lys-Asp-Ala-Leu-Leu-Lys) is a female-attracting peptide pheromone secreted by the abdominal gland of the male red-bellied newt, Cynops pyrrhogaster. Sequence analysis of a cDNA encoding sodefrin revealed that the peptide is located in the C-terminal region of its precursor protein (residues 177-186 of preprosodefrin) and extended from its C-terminus by the tripeptide sequence Ile(187)-Ser(188)-Ala(189) and flanked at its N-terminus by Leu(174)-Gly(175)-Arg(176). This suggests that sodefrin is generated by enzymatic cleavage at monobasic (Lys and Arg) sites within the precursor molecule. To demonstrate the presence in the abdominal gland of proteolytic enzymes capable of generating sodefrin, an enzymatic assay was developed using t-butoxycarbo-nyl (Boc)-Leu-Gly-Arg-4methylcoumaryl-7-amide (MCA) and Boc-Leu-Leu-Lys-MCA as synthetic substrates. A crude extract of the abdominal gland hydrolyzed both substrates to liberate 7-amino-4- methylcoumarin, suggesting that enzymes that generate sodefrin from its precursor molecule are present in the gland. The activity in the extract for cleaving Boc-Leu-Gly-Arg-MCA was optimal at pH 9.0 and 45 degrees C and for Boc-Leu-Leu-Lys-MCA at pH 9.0 and 40 degrees C. The effects of a range of specific inhibitors on activities in the extract suggest an involvement of enzymes belonging to the serine protease family. It was also demonstrated that enzymatic activity in an extract of the abdominal glands of sexually developed males was significantly (three- to six-fold; p<0.01) higher than that of sexually undeveloped males"
Keywords:		Amphibians/*metabolism Animals Hydrogen-Ion Concentration Leucine/analogs & derivatives Male Oligopeptides/*biosynthesis Temperature;
Notes:		"MedlineNakada, Tomoaki Ishizuka, Yoko Iwata, Takeo Toyoda, Fumiyo Kato, Takashi Conlon, J Michael Kikuyama, Sakae eng Research Support, Non-U.S. Gov't Japan 2007/09/18 Zoolog Sci. 2007 May; 24(5):521-4. doi: 10.2108/zsj.24.521"