碩士 / 國立彰化師範大學 / 生物學系 / 93 / Crustacean hyperglycemic hormone (CHH) is a neuropeptide original identified from the X-organ (XO)-sinus gland (SG) complex in the crustacean eyestalk. In the present work, three full-length CHH cDNAs were cloned from the mud crab Scylla olivacea eyestalk ganglia (ES), thoracic ganglia (TG), and per- icardial organ (PO) by RT-PCR and rapid amplification of cDNA end (RACE). PO-CHH and TG-CHH have the same deduced amino acid sequence. TG/PO-CHH and sinus gland CHH (SG-CHH) share an identical N-terminal sequence (amino acids 1-40), but the remaining sequences (amino acids 41-73 or 41-75), differ considerably. The sequence evidence suggests that these two isoforms are derived a Chh gene transcribed in an alternative splicing manner. With the use of a two-step HPLC purification procedure and a CHH isoform- specific ELISA, the two CHH isoforms were isolated from sinus gland and pericardial organ, respectively. Mass spectrometric analysis indicates that the molecular masses for the native SG-CHH and TG/PO-CHH are 8379 Da and 8478 Da, respectively, which are consistent with the estimated values based on the deduced sequences. It also suggests that the two CHHs have a blocked N- terminus, and the C-terminus of SG-CHH is amidated, but TG/PO-CHH has a free C-terminus. The partial amino acid sequences of SG-CHH and TG/PO- CHH were determined by MALDI MS/MS analysis of trypsin-digested peptide fragments. The results show that the amino acid sequences of these peptide fragments were identical to the deduced amino acid sequences of the SG-CHH and TG/PO-CHH cDNAs. In addition, SG-CHH (10 pmole) exhibited a hyper- glycemic activity in vivo, whereas the same dosage of TG/PO-CHH did not elicit a hyperglycemic response. The physiological function of TG/PO-CHH remains to be clarified. We speculate that TG/PO-CHH may have regulatory functions differ from those of SG-CHH.
| Identifer | oai:union.ndltd.org:TW/093NCUE5112016 |
| Date | January 2005 |
| Creators | Kuo-Wei Tsai, 蔡國瑋 |
| Contributors | Chi-Ying Lee, 李奇英 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 114 |
Page generated in 0.0089 seconds