Peter Lewis will join Tuckerbrook Alternative Investments as a general partner at the end of October. He will create a new real estate investment fund and co-manage a real assets fund. Mr. Lewis is currently director of real estate at the Massachusetts Institute of Technology, Cambridge, where he ran a $650 million real estate portfolio. MIT executives have not replaced him, Mr. Lewis said. Calls to Allan Bufferd, MIT treasurer in charge of its $8 billion in endowment and pension assets, were not returned by press time.