Scientific workflows have been established as a ordinary approach adopted by researchers to create simplified views of complex scientific processes. Science portals are a way to simplify the management of large in silico scientific experiments, they aggregate data from different sources and by providing a set of pre-designed analyses. However, such portals are often built manually, and are not flexible enough to support sharing, reusing and executing workflows enacted by SWfMS. In this paper we describe VTPortal, a science portal that combines a set of tools and an infrastructure for providing a collaborative environment for scientists. VTPortal takes into account the requirements of computational scientists, such as accessing high-performance computers and manipulating large amounts of data.