In silico experiments encompass multiple combinations of program and data resources, which are complex to be managed. Typically, script languages are used due to their ease of use, despite their specificity and difficulty of reuse. In contrast, web service technology was specially conceived to encapsulate and combine programs and data, providing interoperation between applications from different platforms. This approach is superior to scripts with regard to interoperability, scalability and flexibility issues. We have combined metadata support with web services within a framework that supports scientific workflows. We have experimented this framework with a real structural genomic workflow, showing its viability and evidencing its advantages.