A Chicago real estate power couple is looking to sell their Gold Coast penthouse. Judd Malkin, who helped build the JMB Realty empire alongside billionaire Neil Bluhm, and Malkin’s wife Katherine, a longtime agent in Chicago’s luxury housing market, have listed their 4,800-square-foot unit in the cooperative building at 1301 North Astor Street, Crain’s reported. […] The post  Real estate royals Judd and Katherine Malkin list Gold Coast penthouse for $5.5M appeared first on The Real Deal.