Open AccessSmall‐Angle X‐Ray and Light‐Scattering Study of Native and Trypsin‐Modified Methionyl‐tRNA Synthetase from Escherichia coli
Author(s) -
GULIK Annette,
MONTEILHET Claude,
DESSEN Philippe,
FAYAT Guy
Publication year - 1976
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1976.tb10300.x
Subject(s) - radius of gyration , scattering , small angle x ray scattering , gyration , crystallography , chemistry , trypsin , radius , molecular physics , enzyme , optics , physics , geometry , polymer , biochemistry , organic chemistry , mathematics , computer security , computer science
Small‐angle X‐ray scattering experiments were performed on an absolute scale on solutions of methionyl‐tRNA synthetase from Escherichia coli in its native and trypsin‐modified forms. A light‐scattering study was performed on the same solutions to verify monodispersity. The structural parameters for the trypsin‐modified enzyme, radius of gyration (2.48 nm), volume (90 nm 3 ), surface/volume (1.5 nm −1 ) and the distribution of chords can account for an equivalent prolate ellipsoid of revolution having an axial ratio 2.3 and a maximum length of 9 nm, with a creviced surface. The results obtained for the native enzyme [i.e. radius of gyration (4.3 nm), volume (244 nm 3 ), distribution of the scattering intensity and distribution of chords] exclude the possibility of a very compact quaternary structure and suggest that the enzyme consists of at least two globular parts, probably the two protomers, linked together by interactions involving a limited region of the structure.