The automated peptide synthesizer, sometimes referred to as a protein synthesizer, was developed by Hood and Stephen B. H. Kent, a senior research associate at Caltech from 1983 to 1989. The peptide synthesizer assembles long peptides and short proteins from amino acid subunits, in quantities sufficient for subsequent analysis of their structure and function. This led to a number of significant results, including the synthesis of HIV-1 protease in a collaboration between Kent and Merck and the analysis of its crystalline structure. Based on this research, Merck developed an important antiprotease drug for the treatment of AIDS. Kent carried out a number of important synthesis and structure-function studies in Hood's lab at Caltech.