title: The structure of Silurus asotus (catfish) roe lectin (SAL): identification of a noncovalent trimer by mass spectrometry and analytical ultracentrifugation.
abstract: We identified a noncovalent trimer of Sirurus asotus roe lectin (SAL) at Mr 95,362 along with its monomer at M(r) 31,750 by electrospray ionization mass spectrometry when SAL was dissolved in 0.5% acetic acid, sprayed into the ion source with methanol as a sheath liquid, and desolvated at 75 degrees C in a heated capillary column. The molecular weight of SAL, determined by the sedimentation equilibrium method, was 95,200 and the sedimentation coefficient (S20,w) of SAL in water was 5.58. SAL existed as a noncovalent trimer in solution and showed the ability to agglutinate rabbit erythrocytes. SAL showed three peaks (sal 1, sal 2, and sal 3) by C8 reverse-phase HPLC, and these appeared to be a monomer, a dimer, and a trimer, respectively, by matrix-assisted laser desorption ionization-time of flight mass spectrometry, sal 1 and sal 2 were shown to have a structure interchangeable with that of sal 3 in water.
authors.affiliation: Division of Biochemical Analysis, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Murayama
authors.forename: H
authors.initials: H
authors.lastname: Taka
authors.forename: N
authors.initials: N
authors.lastname: Kaga
authors.forename: T
authors.initials: T
authors.lastname: Fujimura
authors.forename: R
authors.initials: R
authors.lastname: Mineki
authors.forename: N
authors.initials: N
authors.lastname: Shindo
authors.forename: M
authors.initials: M
authors.lastname: Morita
authors.forename: M
authors.initials: M
authors.lastname: Hosono
authors.forename: K
authors.initials: K
authors.lastname: Nitta
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002397:Catfishes / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D005260:Female; D006386:Hemagglutination Tests; D066298:In Vitro Techniques; D037102:Lectins / Q000737:chemistry* / Q000494:pharmacology; D013058:Mass Spectrometry / Q000379:methods*; D015394:Molecular Structure; D008970:Molecular Weight; D010063:Ovum / Q000737:chemistry; D011487:Protein Conformation; D011817:Rabbits; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014461:Ultracentrifugation / Q000379:methods*
chemical_list: D000596:Amino Acids; D037102:Lectins