RESUMEN
PEG modification is a common clinical strategy for prolonging the half-life of therapeutic proteins or polypeptides. In a previous work, we have successfully synthesized PEG-modified Exendin-4 (PE) by conjugating a 20 kDa PEG to the C-terminal of Exendin-4. Then, we introduced an integrative characterization for PE to evaluate its hypoglycemic activity and pharmacokinetic properties. The normoglycemic efficacies and therapeutic activity of PE were investigated in db/db mice. The hypoglycemic time after single administration of PE on db/db mice was prolonged from 8.4 h to 54.9 h. In multiple treatment with PE, the fasting blood glucose in various PE dosages (50, 150, and 250 nmol/kg) were remarkably reduced, and the glycosylated hemoglobin level was decreased to 2.0%. When the in vivo single- and multiple-dose pharmacokinetics of PE were examined in Sprague-Dawley rats, the half-life was prolonged to 31.7 h, and no accumulation effect was observed. Overall, this study provided a novel promising therapeutic approach to improving glucose-controlling ability and extending half-life without accumulation in vivo for long-acting treatment of type-2 diabetes.
Asunto(s)
Preparaciones de Acción Retardada/administración & dosificación , Preparaciones de Acción Retardada/farmacología , Exenatida/administración & dosificación , Exenatida/farmacología , Hipoglucemiantes , Animales , Glucemia/metabolismo , Células Cultivadas , Preparaciones de Acción Retardada/síntesis química , Preparaciones de Acción Retardada/farmacocinética , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Relación Dosis-Respuesta a Droga , Exenatida/síntesis química , Exenatida/farmacocinética , Resistencia a la Insulina , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos , Ratas Sprague-Dawley , Factores de TiempoRESUMEN
Exendin-4 is a strong therapeutic candidate for the treatment of metabolic syndrome. Related receptor agonist drugs have been on the market since 2005. However, technical limitations and the pain caused by subcutaneous injection have severely limited patient compliance. The goal of the study is to investigate a biologically active exendin-4 analog could be administered orally. Using intraperitoneal glucose tolerance tests, we discovered that exendin4-cysteine administered by oral gavage had a distinct hypoglycemic effect in C57BL/6J mice. Using Rosetta Design and Amber, we designed and screened a series of exendin4-cysteine analogs to identify those that retained biological activity while resisting trypsin digestion. Trypsin Cleavage Site Mutated Exendin4-cysteine 1 (TSME-1), an analog whose bioactivity was similar to exendin-4 and was almost completely resistant to trypsin, was screened out. In addition, TSME-1 significantly normalized the blood glucose levels and the availability of TSME-1 was significantly higher than that of exendin-4 and exendin4-cysteine. Collectively orally administered TSME-1, a trypsin-resistant exendin-4 analog obtained by the system, is a strong candidate for future treatments of type 2 diabetes.
Asunto(s)
Cisteína/genética , Diseño de Fármacos , Receptor del Péptido 1 Similar al Glucagón/agonistas , Mutación , Péptidos/genética , Péptidos/farmacología , Ponzoñas/genética , Ponzoñas/farmacología , Administración Oral , Animales , Disponibilidad Biológica , Glucemia/efectos de los fármacos , AMP Cíclico/metabolismo , Cisteína/química , Diabetes Mellitus Experimental , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Diabetes Mellitus Tipo 2/metabolismo , Exenatida , Receptor del Péptido 1 Similar al Glucagón/química , Prueba de Tolerancia a la Glucosa , Intestino Delgado/enzimología , Masculino , Ratones , Péptido Hidrolasas/metabolismo , Péptidos/administración & dosificación , Péptidos/química , Unión Proteica , Proteolisis , Transducción de Señal/efectos de los fármacos , Relación Estructura-Actividad , Tripsina/metabolismo , Ponzoñas/administración & dosificación , Ponzoñas/químicaRESUMEN
K* is rotamerically ensemble-based approach to compute the binding constant. However, its time-consuming feature limited its application. We present a novel algorithm that not only computes the partition function efficiently, but also avoids the exponential growth of execution time by iteratively pruning the sequence space until the sequence with highest affinity is identified.