PeppyChain, invented by Promita Chakraborty, has interchangeable side chains to make different sequences of amino acids. Hence PeppyChains provides a generic platform to make different proteins. 

More information about making PeppyChain and Peppytide-2 is available at www.quezylab.com and www.peppytides.org

Older models:

Peppytide model files at NIH 3D Print Exchange: http://3dprint.nih.gov/discover/3dpx-001596