RESUMEN
Subvisible particle formation, which occurs after the sterile filtration step of the fill/finish process, is a challenge that may occur during the development of biotherapeutics with complex molecular structures. Here, we show that a stainless steel pump head from a rotary piston pump produces more protein aggregates, past the limit of the acceptable quality range for subvisible particle counts, in comparison to a ceramic pump head. The quartz crystal microbalance was used to quantify the primary layer, proteins irreversibly adsorbed at the solid-liquid interface, and the secondary diffuse gel-like layer interacting on top of the primary layer. The results showed that the mass of protein irreversibly adsorbed onto stainless steel sensors is greater than on an aluminum oxide surface (ceramic pump mimic). This suggests that the amount of adsorbed protein plays a role in surface-induced protein aggregation at the solid-liquid interface.
Asunto(s)
Anticuerpos Monoclonales Humanizados/química , Composición de Medicamentos/métodos , Fragmentos Fc de Inmunoglobulinas/química , Inmunoglobulina G/química , Acero Inoxidable/química , Factor de Necrosis Tumoral alfa/química , Adsorción , Óxido de Aluminio/química , Anticuerpos Monoclonales Humanizados/genética , Cerámica/química , Estabilidad de Medicamentos , Fragmentos Fc de Inmunoglobulinas/genética , Inmunoglobulina G/genética , Agregado de Proteínas , Tecnicas de Microbalanza del Cristal de Cuarzo , Propiedades de Superficie , Factor de Necrosis Tumoral alfa/genéticaRESUMEN
Changes in formulation may be required during the development of protein therapeutics. Some of the changes may alter the protein higher order structure (HOS). In this note, we show how the change from a trehalose-based formulation to an arginine-based formulation concomitantly impacted the tertiary structure and the thermal stability of a mAb (mAb1). The secondary structure was not disrupted by the formulation change. The destabilization of the tertiary structure did not affect the long-term stability or the bioactivity of mAb1. This indicates that loss of conformational stability was likely compensated by improvements in the colloidal stability of mAb1 in the arginine-based formulation. The formulation-induced changes in HOS were reversible as proven by measurements after dilution in a common buffer (phosphate-buffered saline). For aggregation driven by assembly of aggregates (colloidally limited), small changes in conformational structure and stability as measured by HOS methods may not necessarily be predictive of long-term stability.
Asunto(s)
Anticuerpos Monoclonales/química , Productos Biológicos/química , Técnicas de Apoyo para la Decisión , Descubrimiento de Drogas/métodos , Tecnología Farmacéutica/métodos , Arginina/química , Tampones (Química) , Química Farmacéutica , Estabilidad de Medicamentos , Concentración de Iones de Hidrógeno , Agregado de Proteínas , Conformación Proteica , Estabilidad Proteica , Relación Estructura-Actividad , Temperatura , Trehalosa/químicaRESUMEN
Multivalent glycoconjugates were prepared using generation-4 PAMAM dendrimers, and their interaction with Langmuir monolayers containing GM3 was investigated. Excessive carbohydrate valency adversely affects the carbohydrate-carbohydrate interaction. The GM3 monolayer selectively interacts with lactose-functionalized dendrimers in the presence of calcium ions.
Asunto(s)
Carbohidratos/química , Dendrímeros/química , Gangliósido G(M3)/química , Glicoconjugados/síntesis química , Lactosa/química , Glicoconjugados/química , Estructura MolecularRESUMEN
A new class of prodigiosenes with stability-enhancing functionalities appended to the C-ring were found to transport chloride anions through liposomal membranes, as well as to induce copper-mediated DNA cleavage.
Asunto(s)
Cloruros/química , Cobre/química , ADN/química , Prodigiosina/química , Transporte IónicoAsunto(s)
Amidas/química , Cloruros/química , Transportadores de Anión Orgánico/química , Ácidos Ftálicos/química , Amidas/metabolismo , Cloruros/metabolismo , Cristalografía por Rayos X , Enlace de Hidrógeno , Transporte Iónico , Membrana Dobles de Lípidos/química , Membrana Dobles de Lípidos/metabolismo , Liposomas/química , Modelos Moleculares , Conformación Molecular , Transportadores de Anión Orgánico/metabolismo , Ácidos Ftálicos/metabolismoRESUMEN
The C3-symmetric triamide selectively transports NO3- anions across lipid vesicles: this H+-NO3- co-transporter alters the pH inside of liposomes experiencing a NO3-/Cl- gradient.
Asunto(s)
Aniones/química , Cloruros/química , Nitratos/química , Cristalografía por Rayos X , Concentración de Iones de Hidrógeno , Liposomas/química , Modelos Moleculares , Estructura MolecularRESUMEN
This paper describes studies of the carbohydrate-carbohydrate interaction (CCI) between micelles of a lactosyl lipid and monolayers of the glycosphingolipid GM(3). The lactose Lac.GM(3) interaction is involved in B16 melanoma cell adhesion and signaling processes, and a thorough understanding of the molecular details of this CCI is important for the design of new anti-adhesive and anti-metastatic agents. In this paper, we examine the influence of variations in divalent cations and subphase ionic strength on the Lac.GM(3) interaction. Our results indicate that, in the absence of divalent cations, the Lac.GM(3) CCI is strengthened at higher sodium chloride concentrations in the subphase. In contrast, when divalent cations are present in solution, the CCI is not as sensitive to ionic strength. These results suggest a role for both cation dependent as well as independent interactions in the Lac.GM(3) CCI.
