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Studies on heme release from normal and metal ion reconstituted hemoglobin mediated through ionic surfactant
Author(s) -
Venkatesh Balan,
Venkatesh S.,
Jayadevan S.,
Rifkind Joseph M.,
Manoharan P. T.
Publication year - 2004
Publication title -
peptide science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.20194
Subject(s) - chemistry , pulmonary surfactant , hemoglobin , heme , ionic bonding , metal , ion , metal ions in aqueous solution , biophysics , inorganic chemistry , chemical engineering , biochemistry , organic chemistry , enzyme , biology , engineering
The interaction of metal‐substituted hemoglobin (MHb), where M Ni and Cu (T‐state with no O 2 and CO binding capability) and Fe (R‐state when CO is bound), with cationic cityl trimethyl ammonium bromide (CTAB) and anionic (sodium dodecyl sulfate—SDS) surfactants has been studied using spectroscopic techniques—UV‐visible, electron paramagnetic resonance (EPR), and Fourier transform–Raman—with additional supportive evidence coming from conductivity measurements. We observed the loss of 5‐coordination in all three hemoglobins below the critical micelle concentration (CMC) of surfactant, with noticeable differences, suggesting differing mechanisms involved in this process. In addition, above the CMC, Ni‐ and Cu‐hemes were found to leave their proteins more easily than Fe‐heme, presumably due to weaker or no bond with the proximal histidine in the former. The released heme is stabilized by micellar media through a hydrophobic interaction process. Of the two surfactants, CTAB seems to be capable of releasing the heme better than SDS and it is attributed to the greater hydrophobicity of CTAB though the charge of the surfactant plays an important role. © 2004 Wiley Periodicals, Inc. Biopolymers (Pept Sci), 2005