TY - JOUR
T1 - Aplysia attractin
T2 - Biophysical characterization and modeling of a water-borne pheromone
AU - Schein, Catherine H.
AU - Nagle, Gregg T.
AU - Page, Jason S.
AU - Sweedler, Jonathan V.
AU - Xu, Yuan
AU - Painter, Sherry D.
AU - Braun, Werner
N1 - Funding Information:
This work was funded by grants from the UTMB Sealy Center for Structural Biology (to G.T.N., W.B.); Texas Higher Education Coordinating Board Advanced Technology Program (004952-0084-1999 to W.B. and 004952-0002-1999 to G.T.N.); National Science Foundation (IBN-9985778 to S.D.P., DBI-9714937 to W.B., and CHE-9877071 to J.V.S.); National Institutes of Health (NS 31609 to J.V.S.); Department of Energy (DE-FG03-96ER62267 to W.B.); and the Sealy and Smith Foundation.
Funding Information:
We thank B. Clough for expert technical assistance, Lucy Lee for circular dichroism spectra, C. J. Orlea for editing help, and acknowledge the University of Texas Medical Branch (UTMB) Protein Chemistry Laboratory, which is supported by the UTMB Educational Cancer Center, for compositional and microsequence analyses.
PY - 2001
Y1 - 2001
N2 - 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 ∼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 α-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 α-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.
AB - 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 ∼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 α-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 α-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.
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U2 - 10.1016/S0006-3495(01)75714-1
DO - 10.1016/S0006-3495(01)75714-1
M3 - Article
C2 - 11423429
AN - SCOPUS:0034956711
SN - 0006-3495
VL - 81
SP - 463
EP - 472
JO - Biophysical Journal
JF - Biophysical Journal
IS - 1
ER -