Rivoflavin may interfere with on-line monitoring of secreted green fluorescence protein fusion proteins in Pichia pastoris

Background: Together with the development of optical sensors, fluorometry is becoming an increasingly attractive tool for the monitoring of cultivation processes. In this context, the green fluorescence protein (GFP) has been proposed as a molecular reporter when fused to target proteins to study th...

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Detalles Bibliográficos
Autores: Surribas Casalprim, Anna, Resina Rodríguez, David, Ferrer, Pau|||0000-0002-5287-4127, Valero, Francisco|||0000-0003-0429-9620
Tipo de recurso: artículo
Fecha de publicación:2007
País:España
Institución:Universitat Autònoma de Barcelona
Repositorio:Dipòsit Digital de Documents de la UAB
Idioma:inglés
OAI Identifier:oai:ddd.uab.cat:112890
Acceso en línea:https://ddd.uab.cat/record/112890
https://dx.doi.org/urn:doi:10.1186/1475-2859-6-15
Access Level:acceso abierto
Descripción
Sumario:Background: Together with the development of optical sensors, fluorometry is becoming an increasingly attractive tool for the monitoring of cultivation processes. In this context, the green fluorescence protein (GFP) has been proposed as a molecular reporter when fused to target proteins to study their subcellular localization or secretion behaviour. The present work evaluates the use of the GFP fusion partner for monitoring extracellular production of a Rhizopus oryzae lipase (ROL) in Pichia pastoris by means of 2D-fluorimetric techniques. Results: In this study, the GFP-ROL fusion protein was successfully produced as a secreted fusion form in P. pastoris batch cultivations. Furthermore, both the fusion enzyme and the fluorescent protein (GFP S65T mutant) retained their biological activity. However, when multiwavelength spectrofluorometry was used for extracellular fusion protein monitoring, riboflavin appeared as a major interfering component with GFP signal. Only when riboflavin was removed by ultrafiltration from cultivation supernatants, GFP fluorescence signal linearly correlated to lipase activity. Conclusion: P. pastoris appears to secrete/excrete significant amounts of riboflavin to the culture medium. When attempting to monitor extracellular protein production in P. pastoris using GFP fusions combined with multiwavelength spectrofluorimetric techniques, riboflavin may interfere with GFP fluorescence signal, thus limiting the application of some GFP variants for on-line extracellular recombinant protein quantification and monitoring purposes.