| Title: | Aplysia attractin: biophysical characterization and modeling of a water-borne pheromone |
| Author(s): | Schein CH; Nagle GT; Page JS; Sweedler JV; Xu Y; Painter SD; Braun W; |
| Address: | "Sealy Center for Structural Biology, Department of Human Biological Chemistry and Genetics, Galveston, Texas 77555, USA" |
| DOI: | 10.1016/S0006-3495(01)75714-1 |
| ISSN/ISBN: | 0006-3495 (Print) 1542-0086 (Electronic) 0006-3495 (Linking) |
| Abstract: | "Attractin, a 58-residue protein secreted by the mollusk Aplysia californica, stimulates sexually mature animals to approach egg cordons. Attractin from five different Aplysia species are approximately 40% identical in sequence. Recombinant attractin, expressed in insect cells and purified by reverse-phase high-performance liquid chromatography (RP-HPLC), is active in a bioassay using A. brasiliana; its circular dichroism (CD) spectrum indicates a predominantly alpha-helical structure. Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) characterization of proteolytic fragments identified disulfide bonds between the six conserved cysteines (I-VI, II-V, III-IV, where the Roman numeral indicates the order of occurrence in the primary sequence). Attractin has no significant similarity to any other sequence in the database. The protozoan Euplotes pheromones were selected by fold recognition as possible templates. These diverse proteins have three alpha-helices, with six cysteine residues disulfide-bonded in a different pattern from attractin. Model structures with good stereochemical parameters were prepared using the EXDIS/DIAMOD/FANTOM program suite and constraints based on sequence alignments with the Euplotes templates and the attractin disulfide bonds. A potential receptor-binding site is suggested based on these data. Future structural characterization of attractin will be needed to confirm these models" |
| Keywords: | "Amino Acid Sequence Animals Aplysia/*chemistry Circular Dichroism Disulfides/metabolism Glycoproteins/*chemistry/*metabolism *Models, Molecular Molecular Sequence Data Pheromones/*chemistry/*metabolism Protein Folding Protein Structure, Secondary Recombin;" |
| Notes: | "MedlineSchein, C H Nagle, G T Page, J S Sweedler, J V Xu, Y Painter, S D Braun, W eng Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S. 2001/06/26 Biophys J. 2001 Jul; 81(1):463-72. doi: 10.1016/S0006-3495(01)75714-1" |
