Cloning, overexpression and characterization of micro-myoglobin, a minimal heme-binding fragment.
We report the cloning and expression of micro-myoglobin, a 78-amino-acid fragment containing residues 29-105 of sperm whale myoglobin, and spanning the region from mid-helix B to mid-helix G of the globin fold. In contrast to full-length myoglobin and to mini-myoglobin (residues 32-129), the micro-myoglobin apoprotein is almost unfolded. However, circular dichroism and absorption spectroscopy data indicate that this fragment is capable of folding into a functional heme-binding unit forming a complex with the prosthetic group with characteristics similar to native myoglobin. Therefore, this case represents a new example of cofactor-assisted folding. The experimental data suggest independence between myoglobin subdomains.
Grandori
R
R
Institute of Chemistry, Johannes Kepler University, Linz, Austria.
Schwarzinger
S
S
Müller
N
N
D000595:Amino Acid Sequence; D000818:Animals; D002942:Circular Dichroism; D003001:Cloning, Molecular; D015870:Gene Expression; D006418:Heme / Q000378:metabolism*; D006801:Humans; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009211:Myoglobin / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D010446:Peptide Fragments / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D011485:Protein Binding; D017510:Protein Folding; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D016415:Sequence Alignment; D012995:Solubility; D013053:Spectrophotometry; D014907:Whales
D009211:Myoglobin; D010446:Peptide Fragments; D011994:Recombinant Proteins; D006418:Heme