TY - JOUR
T1 - Coulomb instability of multicharged proteins
AU - Jortner, Joshua
AU - Last, Isidore
AU - Levy, Yaacov
N1 - Funding Information:
We thank Claude Guet and Thomas Leisner for useful discussions. This research was supported by the Binational German-Israeli James Franck program on laser–matter interaction and by the Deutsche Forschungsgemeinschaft (DFG) SFB 450 on “Analysis and Control of Ultrafast Photoinduced Reactions”.
PY - 2006/3/1
Y1 - 2006/3/1
N2 - We studied the energetics and fragmentation patterns of multicharged (A+)n Morse clusters (n = 55-321), with a total cluster charge Z = n. The Morse pair-potential parameters were characterized by the dissociation energy D = 1-10 eV, range parameter α = 1-3 Å-1, and interatomic equilibrium separation Re = 1-3 Å. The potential energies ε (per particle) of these multicharged Morse clusters at their equilibrium configuration (with bond length r 0) were analyzed in terms of the liquid drop model. This resulted in the relation ε =(āC0/r0)n 2/3+(āv0D/αr0) +[ās0D/(αr0)3/2]n -1/3, where the reduced parameters āC0 (for the Coulomb energy), āv0 (for the interior energy) and ās0 (for the surface energy) are independent of the Morse pair-potential parameters. The Rayleigh fissibility parameter X = E(Coulomb)/2E(surface), which determines the fragmentation pattern (i.e., X < 1 for cluster fission and X > 1 for Coulomb explosion), was expressed in the form X=(Z2/n)[(2ās 0/āC0)(D/α3/2r 01/2)]-1. The application of this result to the Coulomb instability of multicharged globular proteins reveals that X < 1 for the currently available data. The dominating fragmentation channel is expected to involve spatially anisotropic protein fission into a small number of large fragments, rather than spatially isotropic protein Coulomb explosion into a large number of small fragments.
AB - We studied the energetics and fragmentation patterns of multicharged (A+)n Morse clusters (n = 55-321), with a total cluster charge Z = n. The Morse pair-potential parameters were characterized by the dissociation energy D = 1-10 eV, range parameter α = 1-3 Å-1, and interatomic equilibrium separation Re = 1-3 Å. The potential energies ε (per particle) of these multicharged Morse clusters at their equilibrium configuration (with bond length r 0) were analyzed in terms of the liquid drop model. This resulted in the relation ε =(āC0/r0)n 2/3+(āv0D/αr0) +[ās0D/(αr0)3/2]n -1/3, where the reduced parameters āC0 (for the Coulomb energy), āv0 (for the interior energy) and ās0 (for the surface energy) are independent of the Morse pair-potential parameters. The Rayleigh fissibility parameter X = E(Coulomb)/2E(surface), which determines the fragmentation pattern (i.e., X < 1 for cluster fission and X > 1 for Coulomb explosion), was expressed in the form X=(Z2/n)[(2ās 0/āC0)(D/α3/2r 01/2)]-1. The application of this result to the Coulomb instability of multicharged globular proteins reveals that X < 1 for the currently available data. The dominating fragmentation channel is expected to involve spatially anisotropic protein fission into a small number of large fragments, rather than spatially isotropic protein Coulomb explosion into a large number of small fragments.
KW - Coulomb explosion
KW - Liquid drop model
KW - Morse cluster
KW - Multicharged protein
UR - http://www.scopus.com/inward/record.url?scp=33344466494&partnerID=8YFLogxK
U2 - 10.1016/j.ijms.2005.12.029
DO - 10.1016/j.ijms.2005.12.029
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AN - SCOPUS:33344466494
VL - 249-250
SP - 184
EP - 190
JO - International Journal of Mass Spectrometry
JF - International Journal of Mass Spectrometry
SN - 1387-3806
ER -