[Single amino acid substitutions in the Ca2+-binding site of recoverin.II.The unusual behavior of the protein upon the binding of calcium ions].
The structural properties of myristoylated forms of recombinant recoverin of the wild type and of its mutants with damaged second and/or third Ca(2+)-binding sites were studied by fluorimetry and circular dichroism. The interaction of wild-type recoverin with calcium ions was shown to induce unusual structural rearrangements in its molecule. In particular, protein binding with Ca2+ ions results in an increase in the mobility of the environment of Trp residues, in higher hydrophobicity, and in elevated thermal stability (its thermal transition shifts by 15 degrees C to higher temperatures) but has almost no effect on its secondary structure. Similar structural changes induced by Ca2+ are also characteristic of the -EF2 mutant of recoverin whose second Ca(2+)-binding site is modified and cannot bind calcium ions. The structural properties of the -EF3 and -EF2,3 mutants (whose third or simultaneously second and third Ca(2+)-binding sites, respectively, are modified and damaged) are practically indifferent to calcium ions.
Uverskiĭ
V N
VN
Institute for Biological Instrument Making, Russian Academy of Sciences, Pushchino, Russia.
Permiakov
S E
SE
Senin
I I
II
Cherskaia
A M
AM
Shul'ga-Morskoĭ
S V
SV
Zinchenko
D V
DV
Alekseev
A M
AM
Zargarov
A A
AA
Lipkin
V M
VM
Filippov
P P
PP
Permiakov
E A
EA
D019943:Amino Acid Substitution; D001665:Binding Sites; D002118:Calcium / Q000378:metabolism*; D002135:Calcium-Binding Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D005136:Eye Proteins; D051597:Hippocalcin; D008074:Lipoproteins; D009419:Nerve Tissue Proteins; D011485:Protein Binding; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D051603:Recoverin; D013329:Structure-Activity Relationship
D002135:Calcium-Binding Proteins; D005136:Eye Proteins; D008074:Lipoproteins; D009419:Nerve Tissue Proteins; D011994:Recombinant Proteins; D051603:Recoverin; D051597:Hippocalcin; D002118:Calcium