Premium
Circular Dichroism of Hapten—Antibody Complexes: Characterization of the Combining Sites of Native and Reformed MOPC‐ 315 Protein, Its Isolated Subunits, and Its Fv Fragment
Author(s) -
ROCKEY J. H.,
FREED R. M.
Publication year - 1976
Publication title -
scandinavian journal of immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.934
H-Index - 88
eISSN - 1365-3083
pISSN - 0300-9475
DOI - 10.1111/j.1365-3083.1976.tb03015.x
Subject(s) - hapten , circular dichroism , fragment (logic) , antibody , chemistry , characterization (materials science) , protein subunit , microbiology and biotechnology , stereochemistry , biochemistry , biology , immunology , materials science , nanotechnology , gene , computer science , programming language
Extrinsic Cotton effects generated by binding haptens to native and reformed MOPC‐315 protein, its subunits, and its Fv fragment have been examined. The identity of the combining sites of native and reassociated proteins and Fv‐315 was demonstrated by the identity of their circular dichroism (CD) difference spectra. The spectrum of TNP‐aminocaproate complexed with L chains differed in maxima and minima and cross‐over points and lacked the 495‐nm CD peak of TNP‐aminocaproate‐MOPC‐315 protein and Nα‐TNP‐tryptophan spectra. A negative 293‐nm tryptophanyl CD band, present in spectra of MOPC‐315 proteins and Fv‐315 but absent from spectra of L and H chains, was blue‐shifted by haptens and may represent electronic interactions occurring within the MOPC‐315 combining site between tryptophanyl and chromophoric residues of different subunit. This conclusion is supported by molecular models of the MOPC‐315 combining site.