|Te Brugge, Victoria -|
|Paluzzi, Jean-Paul -|
|Neupert, Susanne -|
|Orchard, Ian -|
Submitted to: Peptides
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 25, 2010
Publication Date: March 1, 2011
Citation: Te Brugge, V., Paluzzi, J., Neupert, S., Nachman, R.J., Orchard, I. 2011. Identification of kinin-related peptides in the disease vector, Rhodnius prolixus. Peptides. 32(3):469-472. Interpretive Summary: Because of problems with the development of resistance to conventional pesticides, there is a critical need for new concepts and alternative approaches in controlling insect pests. The basic premise of this research is that ‘insect kinins’ neuropeptides (short chains of amino acids) serve as potent messengers in insects to regulate water balance and digestion, vital functions in many insects that transmit disease. Nevertheless, these neuropeptides in and of themselves hold little promise as pest control agents because of susceptibility to being degraded in the target pest, and inability to pass through the outside skin and/or digestive tract. We must design neuropeptide mimics that resist degradation by enzymes in the digestive tract and blood of pest invertebrates and interact with the active site within an agricultural or medical pest in such a way as to either over-activate or block critical, neuropeptide-regulated life functions. We report on the identification and characterization of the insect kinins of the assassin bug, an insect that transmits Chaga’s disease to humans. This discovery will aid in the design of neuropeptide-like compounds capable of disrupting the critical life function of water balance and digestion in insect pests. This work brings us one step closer to the development of practical neuropeptide-like substances that will be effective in controlling insect pests that transmit deadly diseases in an environmentally friendly fashion.
Technical Abstract: We have used an in silico approach to identify a gene from the blood-gorging vector, Rhodnius prolixus, that is predicted to produce an insect kinin prepropeptide. The prepropeptide is 398 amino acids in length and can potentially produce a large number of kinin-related peptides following post-translational processing. A comparison with other insect kinin precursor sequences demonstrates greatest conservation at the C-terminal region of the kinin peptides. Multiple peptides predicted from the kinin gene are phenotypically expressed in R. prolixus, as revealed by MALDI-TOF MS MS, including ten peptides with the characteristic kinin C-terminal motif, and five peptides with an untypical, though similar, FX1X2WAamide C-terminus. In addition, there is one peptide with a C-terminal DDNGamide and a number of non-amidated peptides.