The glycolytic enzymes of Trypanosomatids are compartmentalized within peroxisome-like microbodies called glycosomes. Fructose bisphosphate aldolase is synthesized on free polysomes and imported into glycosomes within 5 min. Peptide mapping reveals no primary structural differences between the in vivo-synthesized protein and that made in vitro from a synthetic template. However, native aldolase from glycosomes is partially protease resistant, whereas the in vitro translation product is not. Pulse-chase results indicate that aldolase in bloodstream trypanosomes has a much longer half-life than in the procyclic tsetse fly form.