Porphyrin pi-stacking in a heme protein scaffold tunes gas ligand affinity.

MKGTIVGTWIKTLRDLYGNDVVDESLKSVGWEPDRVITPLEDIDDDEVRRIFAKVSEKTGKNVNEIWREVGRQNIKTLSE
WFPSYFAGRRLVNFLMMMDEVHLQLTKMIKGATPPRLIAKPVAKDAIEMEYVSKRKMYDYFLGLIEGSSKFFKEEISVEE
VERGEKDGFSRLKVRIKFKNPVFEYKKN

0.2 M sodium citrate, pH 4.4, 25% w/v PEG3350, 25 mg/mL protein in 20 mM TEA, pH 7.5, VAPOR DIFFUSION, SITTING DROP

MKGTIVGTWIKTLRDLYGNDVVDESLKSVGWEPDRVITPLEDIDDDEVRRIFAKVSEKTGKNVNEIWREVGRQNIKTFSE
WFPSYFAGRRLVNFLMMMDEVHLQLTKMIKGATPPRLIAKPVAKDAIEMEYVSKRKMYDYFLGLIEGSSKFFKEEISVEE
VERGEKDGFSRLKVRIKFKNPVFEYKKN