Peptide evolution from hormone to weapon

June 18, 2015 / BIOON / - arthropod venom is generally composed of peptide protein toxins By injecting venom into their prey's body, they have a devastating effect on their prey The proteins in the venom are usually thought to come from the proteins produced in arthropods, which are mutated to form toxins that can neutralize other molecules In general, these toxins can bind to different types of ion channel proteins or ion receptor proteins, which leads to the blockage of ion transport in cells, and ultimately leads to the loss of prey's ability to move, which can be slaughtered by hunters   A group of polypeptide proteins widely exist in spider generation, which may belong to the family of ion transport polypeptides (or called crustacean hyperglycemic hormone) In fact, the polypeptides of this family have great differences in function and structure Some of them enter the venom as toxin proteins, and some of them regulate carbohydrate metabolism as hormones   New research shows that a peptide toxin ta1a and a neutralizing toxin have been found in the venom of centipede (close to the evolutionary status of spider) They all come from the family of ion transport polypeptides, that is to say, their ancestors are hormone polypeptides In this centipede, the two polypeptides converged and evolved, and they were all aggregated into the antenna with venom In the process of evolution, these two kinds of peptides have structural and functional adaptation, resulting in their similar structures The researchers compared the structures of two kinds of protein toxins and their ancestors polypeptides (ion transport polypeptides family), and found that they all have similar folding patterns and disulfide bond structures The difference is that, as toxin proteins, they are different from their ancestors in that they lost an alpha helix structure at the C-terminal of the protein These two peptides have evolved independently in arthropods and are used as toxin proteins for animals These polypeptide toxins obtained abnormal stable structure and solubility in the process of evolution, which are called two typical characteristics of toxin protein   The study, published in the journal structure, revealed that the peptide toxins of arthropods have the same origin with some peptide hormones, and there are convergent evolution of these peptide toxins in different species It is also pointed out that most of these toxins originated from hormones are peptides with abnormal and stable structure, so they can be used as skeletons to provide ideas for the research and development of new peptide drugs and insecticides, as well as to further understand the stability of protein structure   This article is the original compilation of Biovalley Welcome to reprint! Please indicate the source of the reprint and attach the original link For more information, please download Biovalley information app.