[Biosynthesis and conformational state of 17-kDa and 27-kDa N-terminal fragments of elongation factor EF-2 in solution].
N-Terminal fragments of the rat liver elongation factor EF-2 containing 162 (17 kDa) and 244 (27 kDa) amino acid residues of 857 (95 kDa) residues of the native protein were synthesized in E. coli cells and in a wheat germ cell-free translation system, and their conformations were studied. Both fragments were synthesized as inclusion bodies (nonspecific molecular aggregates). The conformations of the fragments in a solution were studied at neutral pH values by CD, fluorescence spectroscopy, scanning microcalorimetry, viscosimetry, gel-filtration, limited proteolysis, and interaction with monospecific anti-EF-2 antibodies and GroEL/ES molecular chaperone. Under nondenaturing conditions, both fragments existed in a solution as associates within a broad range of molecular masses, contained a considerable amount of elements of the intramolecular secondary structure, and represented globules without rigid tertiary structure (molten globules). A rigid tertiary structure was not formed even after the interaction of the fragments with the GroEL/ES molecular chaperone, thus indicating that the C-terminal fragment is essential for the formation of the rigid tertiary structure. Both fragments contained conformational antigenic determinants similar to those in the whole protein; i.e., despite the absence of the rigid tertiary structure, the fragments contained elements whose structure was similar to that of the corresponding regions in the whole protein.
Plotnikov
A N
AN
Vasilenko
K S
KS
Kirkitadze
M D
MD
Kotova
N V
NV
Motuz
L P
LP
Korotkov
K V
KV
Semisotnov
G V
GV
Alakhov
Iu B
IuB
D000818:Animals; D015153:Blotting, Western; D002151:Calorimetry; D018835:Chaperonin 10 / Q000378:metabolism; D018834:Chaperonin 60 / Q000378:metabolism; D002850:Chromatography, Gel; D002942:Circular Dichroism; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D008099:Liver / Q000737:chemistry; D020652:Peptide Elongation Factor 2; D010445:Peptide Elongation Factors / Q000737:chemistry* / Q000378:metabolism; D010446:Peptide Fragments / Q000096:biosynthesis* / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D051381:Rats; D012996:Solutions; D013050:Spectrometry, Fluorescence
D018835:Chaperonin 10; D018834:Chaperonin 60; D020652:Peptide Elongation Factor 2; D010445:Peptide Elongation Factors; D010446:Peptide Fragments; D012996:Solutions