Single tryptophanyl substitutions affect the structure of apomyoglobin.
Boll Soc Ital Biol Sper
; 74(9-10): 83-9, 1998.
Article
em En
| MEDLINE
| ID: mdl-10904557
ABSTRACT
Mammalian myoglobins contain two tryptophanyl residues at the invariant positions A-5 (W7) and A-12 (W14) in the N-terminal region (A helix) of the protein molecule. To determine the contribution of each tryptophanyl residue to the structure and stability of myoglobin, recombinant proteins with single indole residue, i.e., W7 or W14, were obtained by site-directed mutagenesis. The mutant proteins, expressed in Escherichia coli, were found correctly folded, the far ultraviolet circular dichroism of both mutants as well as the Soret absorption being superimposed to that of wild type protein. The removal of the prosthetic group from mutant proteins determined a loss of helical content much larger than that observed in the case of wild type myoglobin. These results suggest that tryptophanyl residues can play a crucial role on globin folding and structure.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Apoproteínas
/
Triptofano
/
Mioglobina
Limite:
Animals
Idioma:
En
Revista:
Boll Soc Ital Biol Sper
Ano de publicação:
1998
Tipo de documento:
Article