Transfection efficiency of 25-kDa PEI-cholesterol conjugates with different levels of modification.

This report describes lipophilic conjugates of 25-kDa polyethylenimine (PEI) designed to provide better vectors for nucleic acid transfection. Conjugation of cholesterol is known both to improve transfection properties of PEIs and to reduce their cytotoxic effect. However, extensive modification would significantly decrease the polymer overall positive charge, resulting in less efficient condensation and poor delivery of nucleic acids into cells.

[Chemical ribonucleases: VII. Effect of positively charged RNA-binding domains and hydrophobic fragments of the conjugates based on 1,4-diazabicyclo[2.2.2]octane and imidazol on their ribonuclease activity].

The effect of the total positive charge in the RNA-binding domain of chemical ribonucleases that are conjugates of bisquaternary salts of diazabicyclo[2.2.2]octane and imidazol on the cleavage of an HIV-1 RNA fragment was studied.

[Kinetic parameters of hydrolysis of CpA and UpA sequences in an oligoribonucleotide by compounds functionally mimicking ribonuclease A].

Kinetic parameters of cleavage of CpA and UpA sequences in an oligoribonucleotide under the action of artificial ribonuclease ABL3C1 were measured. The compounds were built of RNA-binding domain B, catalytic fragment C, linker L3 comprising 3 methylene groups, and aliphatic fragment A. The rate of cleavage of phosphodiester bonds in CpA sequence within decaribonucleotide UUCAUGUAAA was shown to be 3.