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Cell interactions of enkephalin/polypeptide conjugates
Author(s) -
Tsukada Motohiko,
SasakiYagi Yoshiko,
Kimura Shunsaku,
Imanishi Yukio
Publication year - 1991
Publication title -
journal of molecular recognition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.401
H-Index - 79
eISSN - 1099-1352
pISSN - 0952-3499
DOI - 10.1002/jmr.300040106
Subject(s) - chemistry , conjugate , fibroblast , receptor , rhodamine , enkephalin , fluorescence , membrane , fluorescence microscope , biophysics , cell membrane , biochemistry , in vitro , biology , opioid , mathematical analysis , physics , mathematics , quantum mechanics
Enkephalin molecules were bound to poly(Lys) (poly‐K) or poly(Ala‐Lys‐Ala‐Leu) (poly‐A) and their interactions with NG108‐15 cells, platelets, erythrocytes and fibroblast cells were investigated. A fluorescent probe, rhodamine, also was bound to the conjugates for monitoring interactions with these cells. Observations by fluorescence microscopy revealed that NG108‐15 cells, and fibroblast cells were labelled by the conjugates, whereas erythrocytes were not. Since polypeptides without enkephalin moieties were only weakly adsorbed on the cells, it was concluded that the enkephalin/polypeptide conjugates were bound specifically to receptors on the cells membrane. Interestingly, when the enkephalin/poly‐K conjugate was bound to NG108‐15 and fibroblast cells, fluorescent patches appeared on the membrane. Such patch formation was not clearly observed with an enkephalin/rhodamine or enkephalin/poly‐A conjugate. In the case of fibroblast cells, the fluorescence converged to a large cluster, which was ultimately internalized. The results suggest that clustering of the receptors in cell membranes in influenced by the carrier polymer presumably due to cross‐linking of the receptors and/or the effect of the cationic polypeptides.