A prominent St. Louis businessman has filed a legal malpractice suit against Bryan Cave, alleging that the firm botched his prenuptial agreement, causing him $10 million in losses tied in part to the appreciation of his high-profile modern art collection, which includes works by Jackson Pollack and Jasper Johns.

Donald Bryant claimed that Bryan Cave partner Lawrence Brody failed to factor in the capital gains tax on the marital estate that Bryant shared with his former wife, Barbara.