title: First protein and peptide characterization of the tarsal adhesive secretions in the desert locust, Schistocerca gregaria, and the Madagascar hissing cockroach, Gromphadorhina portentosa.
abstract: Peptides and proteins have been largely neglected in the analysis of insect tarsal adhesives. After extraction of the protein fraction of the tarsal secretion of the desert locust, Schistocerca gregaria, and Madagascar hissing cockroach, Gromphadorhina portentosa, we combined Fourier transform infrared spectroscopy (FTIR), sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOF MS) analyses for protein mass detection. In both these insects, SDS-PAGE analysis revealed several protein bands ranging from 8-190 kDa in both the tarsal secretion and the tibia control sample. Two (S. gregaria) and one (G. portentosa) protein bands exclusively occurred in the tarsal secretion and can be considered to belong to peptides and proteins specific to this secretion. MALDI-TOF analyses revealed 83 different proteins/peptides of 1-7 kDa in S. gregaria, and 48 of 1-11 kDa in G. portentosa. 59 (S. gregaria) and 27 (G. portentosa) proteins exclusively occurred in the tarsal secretion. In G. portentosa, a characteristic series of signal peaks occurred in the range of c. 10-12 kDa, each peak being approximately 160 Da apart. Such a pattern is indicative of proteins modified by glycosylation. Our approach demonstrates that extensive sampling involving considerable time and manpower to sample the adhesive fluid directly from the tarsi opens up a perspective for extracting peptides and proteins in sufficient quantities. This makes them accessible to the field of proteomics and thus to elucidate their possible function in the adhesive process.
authors.affiliation: Professur für Evolutionsbiologie der Invertebraten, Universität Tübingen, Institut für Evolution und Ökologie, Tübingen, Germany.
authors.forename: O
authors.initials: O
authors.lastname: Betz
authors.affiliation: Medizinisch-Naturwissenschaftliches Forschungszentrum, Tübingen, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Maurer
authors.affiliation: Professur für Evolutionsbiologie der Invertebraten, Universität Tübingen, Institut für Evolution und Ökologie, Tübingen, Germany.
authors.forename: A N
authors.initials: AN
authors.lastname: Verheyden
authors.affiliation: Professur für Evolutionsbiologie der Invertebraten, Universität Tübingen, Institut für Evolution und Ökologie, Tübingen, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Schmitt
authors.affiliation: Fraunhofer-Institut für Fertigungstechnik und Angewandte Materialforschung, Bremen, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Kowalik
authors.affiliation: Professur für Evolutionsbiologie der Invertebraten, Universität Tübingen, Institut für Evolution und Ökologie, Tübingen, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Braun
authors.affiliation: Fraunhofer-Institut für Fertigungstechnik und Angewandte Materialforschung, Bremen, Germany.
authors.forename: I
authors.initials: I
authors.lastname: Grunwald
authors.affiliation: Fraunhofer-Institut für Fertigungstechnik und Angewandte Materialforschung, Bremen, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Hartwig
authors.affiliation: Professur für Evolutionsbiologie der Invertebraten, Universität Tübingen, Institut für Evolution und Ökologie, Tübingen, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Neuenfeldt
mesh_terms: D000818:Animals; D003058:Cockroaches / Q000737:chemistry*; D004591:Electrophoresis, Polyacrylamide Gel; D006110:Grasshoppers / Q000737:chemistry*; D019476:Insect Proteins / Q000032:analysis*; D010455:Peptides / Q000032:analysis; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D019476:Insect Proteins; D010455:Peptides
keywords: FTIR; Insecta; MALDI-TOF MS; PAGE; adhesion; locomotion; peptide; protein; secretion