TY - JOUR
T1 - Strategies to target kyotorphin analogues to the brain
AU - Chen, Pei
AU - Bodor, Nicholas
AU - Wu, Whei Mei
AU - Prokai, Laszlo
PY - 1998/9/24
Y1 - 1998/9/24
N2 - The design, synthesis, and pharmacological evaluation of brain-targeted chemical delivery systems (CDS) for a kyotorphin analogue (Tyr-Lys) are described. The brain-targeted compound contains the active peptide in a packaged, disguised form, flanked between the lipophilic cholesteryl ester on the C-terminus and the 1,4-dihydrotrigonellyl redox targetor, attached to the N-terminus through strategically selected L-amino acid(s) spacer. It was found that for successful brain targeting, the ε-amine of Lys needs to be also converted to a lipophilic function. Through sequential enzymatic bioactivation, the Tyr-Lys dipeptide is released in a sustained manner, producing significant and prolonged analgesic activity as demonstrated by the rat tail latency test. An alternate strategy was also employed. Lys was replaced by a redox amino acid pair, Nys+ mutually implies Nys, the nicotinamide mutually implies 1,4-dihydronicotinamide analogues of Lys (Nys+ is 2-amino-6-(3-carbamoyl-1-pyridiniumyl)hexanoic acid). The Nys form is lipophilic and facilitates delivery in addition to the C- and N-terminal lipophilic functions. Enzymatic oxidation to Nys+ provides the lock-in, followed by removal of the lipophilic groups, releasing Tyr-Nys+ from the brain-targeted analogue (BTRA). Nys+ was shown to be an effective substitution for Arg or Lys. The activities of the CDS and BTRA, respectively, were antagonized by naloxone, supporting the designed brain- targeted processes. The most potent compound is the two-proline spacer containing CDS (CDS-PP), followed by the BTRA.
AB - The design, synthesis, and pharmacological evaluation of brain-targeted chemical delivery systems (CDS) for a kyotorphin analogue (Tyr-Lys) are described. The brain-targeted compound contains the active peptide in a packaged, disguised form, flanked between the lipophilic cholesteryl ester on the C-terminus and the 1,4-dihydrotrigonellyl redox targetor, attached to the N-terminus through strategically selected L-amino acid(s) spacer. It was found that for successful brain targeting, the ε-amine of Lys needs to be also converted to a lipophilic function. Through sequential enzymatic bioactivation, the Tyr-Lys dipeptide is released in a sustained manner, producing significant and prolonged analgesic activity as demonstrated by the rat tail latency test. An alternate strategy was also employed. Lys was replaced by a redox amino acid pair, Nys+ mutually implies Nys, the nicotinamide mutually implies 1,4-dihydronicotinamide analogues of Lys (Nys+ is 2-amino-6-(3-carbamoyl-1-pyridiniumyl)hexanoic acid). The Nys form is lipophilic and facilitates delivery in addition to the C- and N-terminal lipophilic functions. Enzymatic oxidation to Nys+ provides the lock-in, followed by removal of the lipophilic groups, releasing Tyr-Nys+ from the brain-targeted analogue (BTRA). Nys+ was shown to be an effective substitution for Arg or Lys. The activities of the CDS and BTRA, respectively, were antagonized by naloxone, supporting the designed brain- targeted processes. The most potent compound is the two-proline spacer containing CDS (CDS-PP), followed by the BTRA.
UR - http://www.scopus.com/inward/record.url?scp=0032563852&partnerID=8YFLogxK
U2 - 10.1021/jm970715l
DO - 10.1021/jm970715l
M3 - Article
C2 - 9748352
AN - SCOPUS:0032563852
SN - 0022-2623
VL - 41
SP - 3773
EP - 3781
JO - Journal of Medicinal Chemistry
JF - Journal of Medicinal Chemistry
IS - 20
ER -