@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.}
}
@article {5053,
	title = {Detection of noncovalent complex between alpha-amylase and its microbial inhibitor tendamistat by electrospray ionization mass spectrometry},
	journal = {Rapid Communications in Mass Spectrometry},
	volume = {15},
	number = {2},
	year = {2001},
	note = {ISI Document Delivery No.: 396KYTimes Cited: 11Cited Reference Count: 58},
	pages = {89-96},
	type = {Article},
	abstract = {Electrospray ionization mass spectrometry (ESI-MS) is now routinely used for detection of noncovalent complexes. However, detection of noncovalent protein-protein complexes is not a widespread practice and still produces some challenges for mass spectrometrists. Here we demonstrate the detection of a noncovalent protein-protein complex between alpha -amylase and its microbial inhibitor tendamistat using ESI-MS. Crude porcine pancreatic alpha -amylase was purified using a glycogen precipitation method. Noncovalent complexes between porcine pancreatic alpha -amylase and its microbial inhibitor tendamistat are probed and detected using ESI-MS. The atmosphere-vacuum ESI conditions along with solution conditions and the ratio of inhibitor over enzyme strongly affect the detection of noncovalent complexes in the gas phase. ESI mass spectra of alpha -amylase at pH 7 exhibited charge states significantly lower than that reported previously, which is indicative of a native protein conformation necessary to produce a noncovalent complex. Detection of noncovalent complexes in the gas phase suggests that further use of conventional biochemical approaches to provide a qualitative, and in some cases even quantitative, characterization of equilibria of noncovalent complexes in solution is possible. Copyright (C) 2001 John Wiley \& Sons, Ltd.},
	keywords = {ANALYTICAL ULTRACENTRIFUGATION, BINDING, CRYSTAL-STRUCTURE, CYTOCHROME-C, GAS-PHASE, HEME, MYOGLOBIN, PROBING CONFORMATIONAL-CHANGES, PROTEIN PROTEINASE-INHIBITORS, RECOGNITION SITES},
	isbn = {0951-4198},
	url = {<Go to ISI>://000166636600003},
	author = {Douglas, D. J. and Collings, B. A. and Numao, S. and Nesatyy, V. J.}
}
@article {5156,
	title = {Ground-state high-spin iron (III) octaethylporphyrin as studied by single-crystal cw/pulsed ESR spectroscopy},
	journal = {Synthetic Metals},
	volume = {121},
	number = {1-3},
	year = {2001},
	note = {ISI Document Delivery No.: 434TDTimes Cited: 0Cited Reference Count: 616th International Conference on Science and Technology of Synthetic Metals (ICSM 2000)JUL 15-21, 2000GASTEIN, AUSTRIASp. Iss. SI},
	month = {Mar},
	pages = {1820-1821},
	type = {Proceedings Paper},
	abstract = {The g-tensor and relaxation mechanism of ground-state high-spin [Fe(III)OEP]Cl (OEP:octaethylporphyrin) magnetically diluted in diamagnetic NI(IT)OEP single crystals were determined by cw- and pulsed-ESR spectroscopy. From cw-ESR measurements the degree of the rhombicity in fine-structure interaction was determined. It was suggested that the rhombicity is attributable to the pseudo Jahn-teller effect and that the line broadening with increasing temperature is due to the dynamic Jahn-Teller phenomenon among the distorted structures. The large fine-structure constant D was determined to be +7 cm(-1) by measuring the dependences of the spin-lattice relaxation rate on the temperature with the magnetic field perpendicular to the porphyrin plane. The spin-lattice relaxation times highly depend on the direction of the static magnetic field. The orientation dependence was interpreted in terms of the spin sublevel mixing by the spin-orbit interaction.},
	keywords = {electron spin resonance, HEME},
	isbn = {0379-6779},
	url = {<Go to ISI>://000168831200341},
	author = {Nishio, T. and Yokoyama, S. and Sato, K. and Shiomi, D. and Ichimura, A. S. and Lin, W. C. and Dolphin, D. and McDowell, C. A. and Takui, T.}
}
@article {4029,
	title = {Acid-induced unfolding of cytochrome c at different methanol concentrations: Electrospray ionization mass spectrometry specifically monitors changes in the tertiary structure},
	journal = {Biochemistry},
	volume = {36},
	number = {40},
	year = {1997},
	note = {ISI Document Delivery No.: YA264Times Cited: 132Cited Reference Count: 51},
	month = {Oct},
	pages = {12296-12302},
	type = {Article},
	abstract = {The acid-induced denaturation of ferricytochrome c (cyt c) was examined in aqueous solutions containing different concentrations of methanol by electrospray ionization mass spectrometry (ESI MS) and optical spectroscopy. Circular dichroism, fluorescence, and absorption spectroscopy show that at a low concentration of methanol (3\%) a decrease in pH induces a cooperative unfolding transition at around pH 2.6 that is accompanied by a breakdown of the native secondary and tertiary structure of the protein. In 50\% methanol the breakdown of the tertiary structure occurs at around pH 4.0, whereas the alpha-helical content remains largely intact over the whole pH range studied. In ESI MS different protein conformations in solution are monitored by the different charge state distributions they generate during ESI. The ESI mass spectra recorded at near-neutral pH for both methanol concentrations are very similar and show a maximum at (cyt c + 8H(+))8(+). Despite the different conformations of the protein in solution, the acid-denatured states for the two methanol concentrations also show very similar mass spectra with a maximum at (cyt c + 17H(+))17(+). This indicates that the charge state distribution generated during EST is not sensitive to the differences in the secondary structure of the denatured protein. The observed transition from low to high charge states is due to the breakdown of the tertiary structure in both cases. These findings suggest that ESI MS might be a general method to selectively monitor changes in the tertiary structure of proteins.},
	keywords = {ALPHA-HELIX, BETA-LACTOGLOBULIN, CIRCULAR-DICHROISM, DENATURED, FERRICYTOCHROME-C, HEME, PARTIALLY FOLDED STATE, PROBING CONFORMATIONAL-CHANGES, PROTEIN, STATE, TRIFLUOROETHANOL},
	isbn = {0006-2960},
	url = {<Go to ISI>://A1997YA26400034},
	author = {Konermann, L. and Douglas, D. J.}
}
