Abstract: Processes for producing various heterologous polypeptides which when expressed are either incorrectly processed and hence asssociated with the surface of the host cell or are not processed to mature form. More specifically, processes for the production of heterologous non-human carbonyl hydrolases expressed either in host cells incapable of producing enzymatically active endoprotease or host cells deficient in enzymatically active extracellular endoprotease are disclosed. Such non-human carbonyl hydrolases generally are incapable of autoproteolytic maturation and become associated with the surface of expression hosts which are deficient in enzymatically active extracellular endoprotease. Processes for preparing non-human carbonyl hydrolase and heterologous polypeptides which are expressed as part of a fusion polypeptide are also disclosed, as well as non-human carbonyl hydrolases which are substantially free of the host cell membrane with which they are normally associated.