848872-67-3Relevant academic research and scientific papers
Cation dependence of chloride ion complexation by open-chained receptor molecules in chloroform solution
Pajewski, Robert,Ferdani, Riccardo,Pajewska, Jolanta,Li, Ruiqiong,Gokel, George W.
, p. 18281 - 18295 (2007/10/03)
Seventeen peptides, most having the sequence GGGPGGG, but differing in the C- and N-terminal ends, have been studied as anion-complexing agents. These relatively simple, open-chained peptide systems interact with both chloride and the associated cation. Changes in the N- and C-terminal side chains appear to make little difference in the efficacy of binding. NMR studies suggest that the primary interactions involve amide NH contacts with the chloride anion, and CD spectral analyses suggest a concomitant conformational change upon binding. Changes in binding constants, which are expected in different solvents, also suggest selective solvent interactions with the unbound host that helps to preorganize the open-chained peptide system. Significant differences are apparent in complexation strengths when the heptapeptide chain is shortened or lengthened or when the relative position of proline within the heptapeptide is varied.
The C-and N-terminal residues of synthetic heptapeptide ion channels influence transport efficacy through phospholipid bilayers
Djedovic, Natasha,Ferdani, Riccardo,Harder, Egan,Pajewska, Jolanta,Pajewski, Robert,Weber, Michelle E.,Schlesinger, Paul H.,Gokel, George W.
, p. 291 - 305 (2007/10/03)
The synthetic peptide, R2N-COCH2OCH 2CO-Gly-Gly-Gly-PrO-Gly-Gly-Gly-OR′, was shown to be selective for Cl- over K+ when R is n-octadecyl and R′ is benzyl. Nineteen heptapeptides have now been prepared in which the N-terminal and C-terminal residues have been varied. All of the N-terminal residues are dialkyl but the C-terminal chains are esters, 2° amides, or 3° amides. The compounds having varied N-terminal anchors and C-terminal benzyl groups are as follows: 1, R = n-propyl; 2, R = n-hexyl; 3, R = n-octyl; 4, R = n-decyl; 5, R = n-dodecyl; 6, R = n-tetradecyl; 7, R = n-hexadecyl; 8, R = n-octadecyl. Compounds 9-19 have R = n-octadecyl and C-terminal residues as follows: 9, OR′ = OCH2CH3; 10, OR′ = OCH(CH 3)2; 11, OR′ = O(CH2)6CH 3; 12, OR′ = OCH2-c-C6H11; 13, OR′ = O(CH2)9CH3; 14, OR′ = O(CH2)17CH3; 15, NR′2 = N[(CH2)6CH3]2; 16, NHR′ = NH(CH2)9CH3; 17, NR′2 = N[(CH2)9CH3]2; 18, NHR′ = NH(CH2)17CH3; 19, NR′2 = N[(CH2)17CH3]2. The highest anion transport activities were observed as follows. For the benzyl esters whose N-terminal residues were varied, i.e. 1-8, compound 3 was most active. For the C18 anchored esters 10-14, n-heptyl ester 11 was most active. For the C18 anchored, C-terminal amides 15-19, di-n-decylamide 17 was most active. It was concluded that both the C-and N-terminal anchors were important for channel function in the bilayer but that activity was lost unless only one of the two anchoring groups was dominant. The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2005.
