Pitts-McCoy, Anthony M. published the artcileGas-phase ion/ion chemistry as a probe for the presence of carboxylate groups in polypeptide cations, Product Details of C7H16ClNO2, the publication is Journal of the American Society for Mass Spectrometry (2019), 30(2), 329-338, database is CAplus and MEDLINE.
The reactivity of 1-hydroxybenzoyl triazole (HOBt) esters with the carboxylate functionality present in peptides is demonstrated in the gas phase with a doubly deprotonated dianion. The reaction forms an anhydride linkage at the carboxylate site. Upon ion trap collisional-induced dissociation (CID) of the modified peptide, the resulting spectrum shows a nominal loss of the mass of the reagent and a water mol. Analogous phenomenol. was also noted for model peptide cations that likely contain zwitterionic/salt-bridged motifs in reactions with a neg. charged HOBt ester. Control experiments indicate that a carboxylate group is the likely reactive site, rather than other possible nucleophilic sites present in the peptide. These observations suggest that HOBt ester chem. may be used as a chem. probe for the presence and location of carboxylate groups in net pos. charged polypeptide ions. As an illustration, deprotonated sulfobenzoyl HOBt was reacted with the [M+7H]7+ ion of ubiquitin. The ion was shown to react with the reagent and CID of the covalent reaction product yielded an abundant [M+6H-H2O]6+ ion. Comparison of the CID product ion spectrum of this ion with that of the water loss product generated from CID of the unmodified [M+6H]6+ ion revealed the glutamic acid at residue 64 as a reactive site, suggesting that it is present in the deprotonated form.
Journal of the American Society for Mass Spectrometry published new progress about 6249-56-5. 6249-56-5 belongs to chlorides-buliding-blocks, auxiliary class Phase Transfer Catalyst,Inhibitor,Natural product, name is 3-Carboxy-N,N,N-trimethylpropan-1-aminium chloride, and the molecular formula is C7H16ClNO2, Product Details of C7H16ClNO2.
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