TRYPTOPHAN EMISSION FROM HUMAN HEMOGLOBIN AND ITS ISOLATED SUBUNITS

Abstract

Abstract— The emission spectra of human adult hemoglobin A 0 and its isolated α and ß subunits were obtained using a highly sensitive photon‐counting spectrofluorometer. The quantum yields of the emissions, relative to free tryptophan, were also measured as well as the excitation polarization spectra for hemoglobin A 0 and apohemoglobin. The fluorophore bis‐ANS was utilized to probe for the presence of apoproteins in the hemoprotein preparations. The work suggests that tryptophan may be useful as an intrinsic probe to study dynamical processes in hemoglobin.