title: On optima: the case of myoglobin-facilitated oxygen diffusion.
abstract: The process of myoglobin/leghemoglobin-facilitated oxygen diffusion is adapted to function in different environments in diverse organisms. We enquire how the functional parameters of the process are optimized in particular organisms. The ligand-binding properties of the proteins, myoglobin and plant symbiotic hemoglobins, we discover, suggest that they have been adapted under genetic selection pressure for optimal performance. Since carrier-mediated oxygen transport has probably evolved independantly many times, adaptation of diverse proteins for a common functionality exemplifies the process of convergent evolution. The progenitor proteins may be built on the myoglobin scaffold or may be very different.
authors.affiliation: Department of Physiology and Biophysics, Albert Einstein College of Medicine, Bronx, New York 10461, USA. jwitten@post.harvard.edu
authors.forename: Jonathan B
authors.initials: JB
authors.lastname: Wittenberg
mesh_terms: D000818:Animals; D004058:Diffusion; D019143:Evolution, Molecular; D005914:Globins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D006420:Hemeproteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D007700:Kinetics; D007874:Leghemoglobin / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D009211:Myoglobin / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D000078787:Neuroglobin; D010100:Oxygen / Q000737:chemistry / Q000378:metabolism*
chemical_list: D006420:Hemeproteins; D007874:Leghemoglobin; D009211:Myoglobin; D009419:Nerve Tissue Proteins; D000078787:Neuroglobin; D005914:Globins; D010100:Oxygen