Specific alpha-amino acid ester serine hydrolase that prefers small, hydrophobic, and aromatic side chains and does not have a stringent requirement for the leaving group other than preferring a primary alcohol (PubMed:12732646, PubMed:15832508, PubMed:18256025, PubMed:25333274, PubMed:32196348). Has homocysteine-thiolactonase activity (in vitro) and may play a significant role in the detoxification of homocysteine thiolactone in vivo (PubMed:25333274). Catalyzes the hydrolytic activation of amino acid ester prodrugs of nucleoside analogs such as valacyclovir and valganciclovir, converting them into their active forms (acyclovir and ganciclovir) (PubMed:15832508, PubMed:18256025). {ECO:0000269|PubMed:12732646, ECO:0000269|PubMed:15832508, ECO:0000269|PubMed:18256025, ECO:0000269|PubMed:25333274, ECO:0000269|PubMed:32196348}. This is the function of BPHL (biphenyl hydrolase like, Ensembl gene identifier ENSG00000137274).