In particular, in UVPD, specific fragmentation channels are detected, namely formation of radical cations following a hydrogen atom loss and C α–C β bond cleavage fragments. After excitation, direct dissociation in excited states competes with internal conversion to the electronic ground state and with radiative de-excitation. In UV photodissociation (UVPD, 200 nm < λ < 400 nm) and vacuum UV photodissociation (VUVPD, λ < 200 nm), the photon induces an electronic excitation of the peptide. In particular, a better understanding of the different mechanisms involved between the initial excitation event and the experimentally observed fragmentation might allow the development of new strategies for peptide analysis and protein identification. Optical properties of proteins and radical proteins and their relaxation pathways in the VUV range is of fundamental interest to understand the response of biomolecules to radiation and oxidative stresses, and may also have important applications in analytical sciences. Spectra for radical and non-radical ions are quite similar in terms of observed bands however, the VUV fragmentation yield is enhanced by the presence of a radical in caerulein peptides. The detachment yield increases monotonically with the energy with the appearance of several absorption bands. These latter ions are generated by electron photodetachment from 3– precursor ions. We also report photofragment yields as a function of photon energy for doubly deprotonated caerulein ions, for both closed-shell ( 2–) non-radical ions and open-shell ( 2– Thus, there is no memory effect of the initial excitation energy on the fragmentation channels of the oxidized species on the time scale of our tandem MS experiment. The branching ratios of the different fragments observed by CID as a function of the initial VUV photon energy are found to be independent of the initial photon energy. The oxidized ions, generated by electron photodetachment were further isolated and activated by collision (CID) in a MS 3 scheme. However, an increase in the fragmentation efficiency (neutral losses and peptide backbone cleavages) as a function of the energy is also observed. Electron loss is found to be the major relaxation channel at every photon energy. Caerulein is a sulphated peptide with three aromatic residues and nine amide bonds. Powered by Perl 5.028001.We have studied the photodissociation of gas-phase deprotonated caerulein anions by vacuum ultraviolet (VUV) photons in the 4.5 to 20 eV range, as provided by the DESIRS beamline at the synchrotron radiation facility SOLEIL (France). SUPPORT COPE | Intro | Subdictionaries | New Entries | Contribute data | COPE CredentialsĬreated, developed, and maintained by Dr H IbelgauftsĪbout the author of COPE | Contact COPE | Terms & ConditionsĬope.cgi Version 1.41. All rights reserved by Dr H Ibelgaufts, the author of COPE - Cytokines & Cells Online Pathfinder Encyclopaedia ENTRY LAST MODIFIED: December 2006 See example pages at the bottom of the home page THE SMART ONES COPEĬopyright © 1997-2021. Topic-specific introductions, Topic-specific integrated subdictionaries, Scientific references with PubMed links with a 15 USD/month subscription at Nomenclature, concepts, strategies & complexities of cellular communication, includingĮukaryotic cell types & expression profiles |Īccess to Alphabet bar, Freetext search, Leafing/browsing functions, Internal Backlinking, ĬOPE - with 54500+ entries the most comprehensive cell-to-cell communication knowledge baseĮxtensive In-depth and In Context Information covering terminology, Another designation for adenoregulin is Dermaseptin B2. The peptide shares structural and conformational homology with dermaseptins, antimicrobial peptides exhibiting strong membranolytic activities against various pathogenic agents (Amiche et al, 1993 Mor and Nicolas, 1994 Mor et al, 1994 Amiche et al, 1994). The peptide has been shown to enhance binding of agonists to A1 adenosine receptors (Daly et al, 1992 Moni et al, 1995).
#Caerulein precursor fragment 3 skin#
Adenoregulin (Cytokines & Cells Encyclopedia - COPE)Īdenomatosis polyposis coli down-regulated 1Īdenoregulin ( GLWSKIKEVGKEAAKAAAKAAGKAALGAVSEAV) is a peptide isolated from skin secretions of the South-American frog Phyllomedusa bicolor (Daly et al, 1992).
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