6249-56-5Relevant articles and documents
Enhancing electrospray ionization efficiency of peptides by derivatization
Mirzaei, Hamid,Regnier, Fred
, p. 4175 - 4183 (2006)
With the advent of electrospray ionization mass spectrometry, the world was given a new way to look at complex peptide mixtures. Identification of proteins via their signature peptides requires ionization of a representative portion of the peptides derived from proteins by proteolysis. Unfortunately, matrix effects prohibited electrospray ionization of many peptides. This paper describes the development of a new labeling reagent that simultaneously adds a permanent positive charge to peptides and increases their hydrophobicity to enhance their ionization efficiency. The labeling agent is preactivated with N-hydroxysuccinimide to react with primary amines to form a peptide bond. In the most dramatic case, ionization efficiency of the peptide ADRDQYELLCLDNTRKPVDEYK increased 500-fold after derivatization as opposed to other peptides where ionization efficiency was impacted little. Ionization efficiency of peptides was enhanced roughly 10-fold in general by derivatization. Peptides of less than 500 Da experienced the greatest increase in ionization efficiency by derivatization. Poor ionization efficiency of native peptides was found to be due more to their inherent structural properties than the matrix in which ionization occurs.
Nanoscale Biodegradable Organic–Inorganic Hybrids for Efficient Cell Penetration and Drug Delivery
H?rner, Sebastian,Knauer, Sascha,Uth, Christina,J?st, Marina,Schmidts, Volker,Frauendorf, Holm,Thiele, Christina Marie,Avrutina, Olga,Kolmar, Harald
supporting information, p. 14842 - 14846 (2016/11/23)
We report a comprehensive study on novel, highly efficient, and biodegradable hybrid molecular transporters. To this end, we designed a series of cell-penetrating, cube-octameric silsesquioxanes (COSS), and investigated cellular uptake by confocal microscopy and flow cytometry. A COSS with dense spatial arrangement of guanidinium groups displayed fast uptake kinetics and cell permeation at nanomolar concentrations in living HeLa cells. Efficient uptake was also observed in bacteria, yeasts, and archaea. The COSS-based carrier was significantly more potent than cell-penetrating peptides (CPPs) and displayed low toxicity. It efficiently delivered a covalently attached cytotoxic drug, doxorubicin, to living tumor cells. As the uptake of fluorescently labeled carrier remained in the presence of serum, the system could be considered particularly attractive for the in vivo delivery of therapeutics.
Exploiting neighboring-group interactions for the self-selection of a catalytic unit
Gasparini, Giulio,Prins, Leonard J.,Scrimin, Paolo
supporting information; experimental part, p. 2475 - 2479 (2009/02/06)
(Figure Presented) A good neighbor is better than a far-away friend: A tethering strategy is used to self-select groups that assist in the cleavage of a neighboring carboxylic ester moiety (see picture, TSA=transition-state analogue). A correlation is observed between the amplification at thermodynamic equilibrium and the catalytic efficiency.
