{"id":1566,"date":"2018-06-24T21:31:40","date_gmt":"2018-06-24T20:31:40","guid":{"rendered":"http:\/\/ibb.uab.cat\/?p=1566"},"modified":"2018-06-24T21:34:57","modified_gmt":"2018-06-24T20:34:57","slug":"switching-cell-penetrating-and-cxcr4-binding-activities-of-nanoscale-organized-arginine-rich-peptides","status":"publish","type":"post","link":"https:\/\/ibb.uab.cat\/index.php\/2018\/06\/24\/switching-cell-penetrating-and-cxcr4-binding-activities-of-nanoscale-organized-arginine-rich-peptides\/","title":{"rendered":"Switching cell penetrating and CXCR4-binding activities of nanoscale-organized arginine-rich peptides"},"content":{"rendered":"
Abstract<\/strong><\/span><\/p>\n Arginine-rich\u00a0protein motifs<\/a>\u00a0have been described as potent cell-penetrating\u00a0peptides<\/a>\u00a0(CPPs) but also as rather specific ligands of the cell surface\u00a0chemokine receptor<\/a>\u00a0CXCR4<\/a>, involved in the infection by the\u00a0human immunodeficiency virus<\/a>\u00a0(HIV).\u00a0<\/p>\n<\/div>\n Polyarginines are commonly used to functionalize nanoscale vehicles for\u00a0gene therapy<\/a>\u00a0and drug delivery, aimed to enhance cell penetrability of the therapeutic cargo. However, under which conditions these peptides do act as either unspecific or specific ligands is unknown. We have here explored the cell penetrability of differently charged polyarginines in two alternative presentations, namely as unassembled\u00a0fusion proteins<\/a>\u00a0or assembled in\u00a0multimeric protein<\/a>\u00a0nanoparticles<\/a>. By this, we have observed that arginine-rich peptides switch between receptor-mediated and receptor-independent mechanisms of cell penetration. The relative weight of these activities is determined by the electrostatic charge of the construct and the\u00a0oligomerization<\/a>status of the nanoscale material, both regulatable by conventional\u00a0protein engineering<\/a>\u00a0approaches<\/p>\n <\/p>\n