@article {1483,
	title = {Coulomb effects in binding of heme in gas-phase ions of myoglobin},
	journal = {Rapid Communications in Mass Spectrometry},
	volume = {20},
	number = {2},
	year = {2006},
	note = {ISI Document Delivery No.: 003PGTimes Cited: 3Cited Reference Count: 31},
	pages = {111-117},
	type = {Article},
	abstract = {Coulomb effects in binding of heme in gas-phase holomyoglobin ions are studied. Positive and negative ions are formed from solution myoglobin with Fe2+ (ferromyoglobin) and Fe3+ (ferrimyoglobin). The energy that must be added to the resulting holomyoglobin ions to cause heme loss has been measured by triple-quadrupole tandem mass spectrometry. With negative ions, neutral heme is lost regardless of the charge state of Fe in solution. It is likely that the Fe3+ is reduced to Fe2+ in the negative electrospray process. With positive ions, predominantly neutral heme loss is observed with ions formed from ferromyoglobin in solution, and positive heme loss with ions formed from ferrimyoglobin in solution. The energies required to induce neutral heme loss are similar for positive and negative ions. The energies required to induce charged heme loss from positive holomyoglobin ions are significantly less. Coulomb repulsion between the charged heme and charged protein appears to lower the barrier for heme loss. These results are consistent with a simple model potential with a long-range Coulomb repulsion and short-range attraction between the heme and protein. Copyright (c) 2005 John Wiley \& Sons, Ltd.},
	keywords = {B(5), COLLISION CROSS-SECTIONS, CYTOCHROME, DISSOCIATION, ELECTROSTATIC INTERACTIONS, GLOBIN COMPLEXES, HOLOMYOGLOBIN, IONIZATION-MASS-SPECTROMETRY, PROTEINS, STABILITY, ZN-MYOGLOBIN},
	isbn = {0951-4198},
	url = {<Go to ISI>://000234693500006},
	author = {Mark, K. J. and Douglas, D. J.}
}
@article {439,
	title = {Hydrogen/deuterium exchange of myoglobin ions in a linear quadrupole ion trap},
	journal = {Rapid Communications in Mass Spectrometry},
	volume = {16},
	number = {20},
	year = {2002},
	note = {ISI Document Delivery No.: 604ADTimes Cited: 10Cited Reference Count: 26},
	pages = {1941-1945},
	type = {Article},
	abstract = {The hydrogen/deuterium (H/D) exchange of gas-phase ions of holo- and apo-myoglobin has been studied by confining the ions in a linear quadrupole ion trap with D2O or CD3OD at a pressure of several mTorr. Apo-myoglobin ions were formed by collision-induced dissociation of holomyoglobin ions between the orifice and skimmer of the ion sampling system. The exchange takes place on a time scale of seconds. Earlier cross section measurements have shown that holomyoglobin ions can have more compact structures than apo-myoglobin. Despite this, both holomyoglobin and apo-myoglobin in charge states +8 to +14 are found to exchange nearly the same number of hydrogens (ca. 103) in 4 s. It is possible the ions fold or unfold to new conformations on the much longer time scale of the exchange experiment compared with the cross section measurements. Copyright (C) 2002 John Wiley Sons, Ltd.},
	keywords = {COLLISION CROSS-SECTIONS, CYTOCHROME-C, GAS-PHASE, HEME, HOLOMYOGLOBIN, HYDROGEN-DEUTERIUM EXCHANGE, MASS-SPECTROMETRY, OF-FLIGHT, PROTEIN IONS, STABILITY, SYSTEM},
	isbn = {0951-4198},
	url = {<Go to ISI>://000178592700007},
	author = {Mao, D. M. and Ding, C. F. and Douglas, D. J.}
}
