Studying noncovalent protein complexes by electrospray ionization mass spectrometry

Abstract

Electrospray ionization mass spectrometry has been used to baggage carriers, providing transport to important destinastudy protein interactions driven by noncovalent forces. The tions. In other cases, proteins require a partner to fulfill gentleness of the electrospray ionization process allows intact their crucial task in life. Generally, proteins as a class are protein complexes to be directly detected by mass spectrometry.nondiscriminating, interacting with a variety of species, Evidence from the growing body of literature suggests that the such as other proteins, peptides, oligonucleotides, metal ESI-MS observations for these weakly bound systems reflect, to ions, and other small molecules. Several protein systems some extent, the nature of the interaction found in the condensed are functionally active only when one or several copies of phase. Stoichiometry of the complex can be easily obtained from itself are in the vicinity (the quaternary structure of a the resulting mass spectrum because the molecular weight of protein). However, as with the macroscopic world, each the complex is directly measured. For the study of protein interindividual protein species may have preferences for a paractions, ESI-MS is complementary to other biophysical methods, such as NMR and analytical ultracentrifugation. However, mass ticular partner.

Potential for Using Isotopically Altered Metalloproteins in Species-Specific Isotope Dilution Analysis of Proteins by HPLC Coupled to Inductively Coupled Plasma Mass Spectrometry

“…The only consistent features were that the spectra obtained under denaturing conditions contained a much higher number of charge states, as compared to those at neutral pH conditions. These results correspond to other studies that have investigated the noncovalent binding properties of proteins, particularly metalloproteinase enzymes and previous reports on the structure of Rc using electrospray mass spectrometry under acidic conditions. , …”

Probing metal ion binding and conformational properties of the colicin E9 endonuclease by electrospray ionization time‐of‐flight mass spectrometry

“…Despite the very high affinity of the E9 DNase‐Im9 complex observed in solution, in the gas‐phase disruption of the protein–protein interaction occurs before dissociation of the protein–metal ion interaction. This is in accordance with the emerging view that electrostatic interactions are enhanced, whereas the hydrophobic effect becomes less significant in the gas phase (Loo 1997; Smith et al 1997a,b).…”

Determinants of Gas-Phase Disassembly Behavior in Homodimeric Protein Complexes with Related Yet Divergent Structures

“…Thus, it is proposed that the interfacial electrostatic interactions of λ Cro contribute enhanced interface stability in the gas phase, and thus the barrier for subunit unfolding is reached before the barrier for subunit loss. This model is consistent with the asymmetric CID pattern of λ Cro, and is also in concurrence with many examples of enhanced ionic interactions in vacuo. ,− These results also suggest that interfaces lacking salt bridges are more likely to allow complex dissociation to occur with minimal subunit unfolding and thus high charge symmetry, as observed for N15 Cro.…”