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Titolo:
Formation of non-specific protein cluster ions in matrix-assisted laser desorption/ionization: abundances and dynamical aspects
Autore:
Livadaris, V; Blais, JC; Tabet, JC;
Indirizzi:
Lab Chim Struct Organ & Biol, CNRS, UMR 7613, F-75252 Paris 05, France LabChim Struct Organ & Biol Paris France 05 3, F-75252 Paris 05, France Univ Paris 06, F-75252 Paris, France Univ Paris 06 Paris France F-75252Univ Paris 06, F-75252 Paris, France
Titolo Testata:
EUROPEAN JOURNAL OF MASS SPECTROMETRY
fascicolo: 5, volume: 6, anno: 2000,
pagine: 409 - 413
SICI:
1469-0667(2000)6:5<409:FONPCI>2.0.ZU;2-3
Fonte:
ISI
Lingua:
ENG
Soggetto:
TIME-OF-FLIGHT; DOUBLE-STRANDED DNA; DESORPTION-IONIZATION; MASS-SPECTROMETRY; NONCOVALENT COMPLEXES; MALDI; VELOCITY; MS;
Keywords:
MALDI; TOF-MS; protein; non-covalent complexes; dynamics; ion stability;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
15
Recensione:
Indirizzi per estratti:
Indirizzo: Blais, JC Lab Chim Struct Organ & Biol, CNRS, UMR 7613, 4 Pl Jussieu, F-75252 Paris 05, France Lab Chim Struct Organ & Biol 4 Pl Jussieu Paris France 05 rance
Citazione:
V. Livadaris et al., "Formation of non-specific protein cluster ions in matrix-assisted laser desorption/ionization: abundances and dynamical aspects", EUR J MASS, 6(5), 2000, pp. 409-413

Abstract

Intact non-covalent biological complexes resulting from interactions in solutions have been observed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI TOF-MS). However, their analysis is hampered by the presence of non-specific, non-covalent complexes (clusters)produced under MALDI conditions. A study of the influence of laser energy and ion extraction conditions allows information to be obtained on (i) the collision regime in the plume and (ii) ion stability, through the abundances and time-of-flight (t(tof)) deviations of bovine insulin clusters using asinapinic acid matrix, In the linear mode, it is shown that (i) the neutral contribution to quasi-molecular peaks is below 10% and (ii) for related cluster species, the t(tof) difference between neutrals and ions is less than 10 ns, Although the abundance of cluster ions increases relatively to theabundance of the monomeric ions with laser energy, heavier cluster ions are unfavored at higher laser energy. On the other hand, the abundance of clusters is, to a first approximation, independent of the electric field in the first acceleration region (750-32,500 V cm(-1)) and of the extraction delay (up to 4000 ns), Gaussian-like distribution profiles are observed, whatever the acceleration field, for all cluster ion signals. This is in good agreement with the natural isotopic distribution, There is no significant difference between monomeric and cluster ion initial velocities (420 m s(-1) +/- 18 m s(-1)). Our results suggest a single origin for bovine insulin cluster ions that are observed by using a sinapinic acid matrix, The clusters should be formed promptly after the laser pulse (< 10 ns), in the selvedge of the surface. Smaller cluster ions could be formed by consecutive fragmentations of higher mass molecular clusters occurring after plume formation and before a significant ion acceleration.

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Documento generato il 02/07/20 alle ore 22:28:04