caa a22 4500 475744055 CHVBK 20180406123507.0 cr unu---uuuuu 170329e20001001xx s 000 0 eng 10.1023/A:1007150318854 doi (NATIONALLICENCE)springer-10.1023/A:1007150318854 Wavelength-Dependent Spectral Changes Accompany CN-Hemin Binding to Human Apohemoglobin [Elektronische Daten] [Gayathri Vasudevan, Melisenda McDonald] The interaction of apohemoglobin with two heme derivatives, CN-protohemin and CN-deuterohemin, was monitored at multiple Soret wavelengths (417-423 and 406-412 nm, respectively) in 0.05 M potassium phosphate buffer, pH 7.0, at 10°C and revealed, as previously reported, a multiphasic kinetic reaction. Wavelength-dependent reactions were observed for both CN-protohemin and CN-deuterohemin derivatives with the a chain (bathochromic entity) displaying faster (4- to 7-fold) rates throughout the courses of both heme-binding reactions. The basis of this spectrally heterogeneous kinetic phenomenon could be deduced from molecular modeling studies of α- and β-chain structures. Key differences in the number of stabilizing contacts of the two chains with the peripheral a propionyl 45(CE3); 58(E7); 61(E10) as well as the b vinyl 38(C4); 71(E15); 106(G8) groups were found. Furthermore, RMS plots comparing apo- and heme-containing subunits reveal substantial structural disparities in the C-CD-F-FG helical regions of the αβ dimer interface. Plenum Publishing Corporation, 2000 CN-hemin binding kinetics nationallicence apohemoglobin nationallicence chain heterogeneity nationallicence wavelength dependence nationallicence heme peripheral group interactions nationallicence subunit interface nationallicence Vasudevan Gayathri Biochemistry Program, Department of Chemistry, College of Arts and Sciences, University of Massachusetts, 01854, Lowell, Massachusetts aut McDonald Melisenda Biochemistry Program, Department of Chemistry, College of Arts and Sciences, University of Massachusetts, 01854, Lowell, Massachusetts aut Journal of Protein Chemistry Kluwer Academic Publishers-Plenum Publishers 19/7(2000-10-01), 583-590 0277-8033 19:7<583 2000 19 10930 https://doi.org/10.1023/A:1007150318854 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1023/A:1007150318854 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Vasudevan Gayathri Biochemistry Program, Department of Chemistry, College of Arts and Sciences, University of Massachusetts, 01854, Lowell, Massachusetts aut NATIONALLICENCE 700 1- McDonald Melisenda Biochemistry Program, Department of Chemistry, College of Arts and Sciences, University of Massachusetts, 01854, Lowell, Massachusetts aut NATIONALLICENCE 773 0- Journal of Protein Chemistry Kluwer Academic Publishers-Plenum Publishers 19/7(2000-10-01), 583-590 0277-8033 19:7<583 2000 19 10930 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer