258331-08-7Relevant academic research and scientific papers
One-pot formation of hydrazide macrocycles with modified cavities: An example of pH-sensitive unimolecular cation channels
Xin, Pengyang,Tan, Si,Sun, Yonghui,Ren, Qiaojv,Dong, Wenpei,Guo, Jingjing,Jiang, Tao,Chen, Chang-Po
supporting information, p. 5322 - 5325 (2017/07/07)
A series of pH-sensitive, cation-selective hydrazide macrocyclic channels have been synthesized. The macrocyclic channels bear multiple carboxyls in the inner cavity, which have a significant impact on their membrane-incorporation ability and NH4/su
Mechanism of Site-Directed Protein Cross-Linking. Protein-Directed Selectivity in Reactions of Hemoglobin with Aryl Trimesates
Kluger, Ronald,de Stefano, Vittorio
, p. 214 - 219 (2007/10/03)
Site-directed cross-linking of hemoglobin has become an efficient way to produce a structurally defined altered protein with desirable functional properties. The reagent trimesoyl tris(3,5-dibromosalicylate) (1) introduces a bis amide cross-link derived from the ∈-amino groups of the side chains of the two β-Lys-82 residues in human hemoglobin. The basis of its specificity was investigated using a set of analogues of 1 (2-12). There are marked differences in the reaction patterns of these compounds with amino groups in hemoglobin compared to reactions with n-propylamine. The compounds that effectively modify the protein contain a carboxyl group ortho to the phenolic oxygen of the ester, while materials with meta or para carboxyl groups give little or no reaction. In contrast, the reactions with n-propylamine are slowest with the ortho carboxyl materials. Addition of the unreactive compound 5 to a solution containing hemoglobin reduces the ability of 1 to modify the protein, showing that the unreactive compound binds but does not react. On the basis of these observations and the known reaction patterns of salicylates, it is clear that the environment in the protein controls the reaction, regardless of the inherent reactivity of the reagent. We propose that the carboxyl group positions the reagent critically within the protein. Only the ortho arrangement permits transfer of the acyl function to the nucleophile.
