Silicon Valley real estate developer John A. Sobrato and wife Susan Sobrato have gifted $100 million to Santa Clara University to build an undergraduate STEM center. The donation marks the largest gift the university has received and the family has made. The 300,000-square-foot Sobrato Campus for Discovery and Innovation will boost the university's science, technology, engineering and math disciplines. Santa Clara University has seen an 85 percent increase in undergraduate STEM enrollment in the…