Molecular mechanism for ligand stabilization in the mollusc myoglobin possessing the distal Val residue.
Myoglobin extracted from the triturative stomach of Dolabella auricularia, a common mollusc found on the Japanese coast, possesses naturally occurring substitution at the distal E7 position (Val-E7) and its oxygen affinity is only slightly lower than those of the common mammalian myoglobins possessing the usual His-E7. 1H nuclear magnetic resonance studies of Dolabella met-cyano myoglobin have revealed that a guanidino NH proton of Arg-E10 is hydrogen-bonded to the Fe-bound CN-. The role of Arg-E10 as a hydrogen-bond donor for Fe-bound ligand in the present myoglobin appears to be responsible for its relatively high ligand affinity.
Yamamoto
Y
Y
Department of Biomolecular Engineering, Tokyo Institute of Technology, Japan.
Iwafune
K
K
Chûjô
R
R
Inoue
Y
Y
Imai
K
K
Suzuki
T
T
D000818:Animals; D006860:Hydrogen Bonding; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000378:metabolism*; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D008974:Mollusca; D009211:Myoglobin / Q000737:chemistry / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism; D014633:Valine / Q000378:metabolism*
D008024:Ligands; D009211:Myoglobin; D007501:Iron; D014633:Valine; D010100:Oxygen