Denaturation of MM-creatine kinase by sodium dodecyl sulfate.
J Protein Chem
; 15(6): 527-37, 1996 Aug.
Article
em En
| MEDLINE
| ID: mdl-8895099
ABSTRACT
The denaturation of dimeric cytoplasmic MM-creatine kinase by sodium dodecyl sulfate (SDS) has been investigated using activity measurements, far-ultraviolet circular dichroism, SEC-HPLC, electric birefringence, intrinsic probes (cysteine and tryptophan residues), and an extrinsic fluorescent probe (ANS). Our results show that inactivation is the first detectable event; the inactivation curve midpoint is located around 0.9 mM SDS. The second event is dissociation and it occurs in parallel to tertiary and secondary perturbations, as demonstrated by the coincidence (near 1.3 mM) of the midpoints of the transition curves monitoring dissociation and structural changes. At high total SDS concentration (concentration higher than 2.5 mM), the monomer had bound 170 mol of SDS per mol of protein. In these conditions, electric birefringence experiments suggest that the SDS-CK complex may be described as a prolate ellipsoid with an axial ratio of 1.27 (14 nm x 11 nm). These results are compatible with recent models of SDS-protein complexes the "protein decorated micelle structure" or the "necklace structure".
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Base de dados:
MEDLINE
Assunto principal:
Dodecilsulfato de Sódio
/
Creatina Quinase
Idioma:
En
Revista:
J Protein Chem
Ano de publicação:
1996
Tipo de documento:
Article
País de afiliação:
França