title: Conformation and activity of Phaseolus coccineus var. rubronanus lectin.
abstract: The conformation of native and denatured Phaseolus coccineus var. rubronanus lectin was studied by circular dichroism (CD) and correlated to the hemagglutinating activity. The far-UV CD spectrum at 25 degrees C showed a broad, negative band around 223 nm and a positive one at 196 nm. CD data analysis of the lectin indicated a beta-sheet-rich protein. At high temperatures, the spectrum was blue-shifted with increasing magnitude; these changes correlated well with the loss of the activity. The conformation of lectin between pH 2 and 10 remained essentially unchanged. At pH 13 the CD spectrum resembled that of unordered form with a negative band near 200 nm and the activity was completely lost. The denatured lectin in 6 M guanidine hydrochloride would be renatured upon diluting the denaturant to 0.75 M; the changes in CD spectrum again correlated well with the loss of the activity. The effect of sodium dodecyl sulfate on the lectin was drastic; it sharply increased the alpha-helix at the expense of the beta-sheet and reduced the activity; the changes reached a plateau above 20 mM surfactant.
authors: Shanghai Institute of Biochemistry, Academia Sinica, People's Republic of China.
authors: W X
authors: WX
authors: Shi
authors: Z M
authors: ZM
authors: Shen
authors: C
authors: C
authors: Sun
authors: J T
authors: JT
authors: Yang
mesh_terms: D002942:Circular Dichroism; D007887:Fabaceae / Q000737:chemistry*; D019791:Guanidine; D006146:Guanidines; D006384:Hemagglutination; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D037102:Lectins / Q000737:chemistry* / Q000494:pharmacology; D037121:Plant Lectins; D010946:Plants, Medicinal; D011487:Protein Conformation; D011489:Protein Denaturation; D012967:Sodium Dodecyl Sulfate; D013056:Spectrophotometry, Ultraviolet
chemical_list: D006146:Guanidines; D037102:Lectins; D037121:Plant Lectins; D012967:Sodium Dodecyl Sulfate; D019791:Guanidine