Cloning, overexpression and characterization of micro‐myoglobin, a minimal heme‐binding fragment

• Published in: European Journal of Biochemistry
• Main Authors: Grandori, Rita, Schwarzinger, Stephan, Müller, Norbert
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2000
• Subjects: Sperm whale
• Online Access: http://dx.doi.org/10.1046/j.1432-1327.2000.01114.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1046%2Fj.1432-1327.2000.01114.x; https://febs.onlinelibrary.wiley.com/doi/pdf/10.1046/j.1432-1327.2000.01114.x

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.