PMID-sentid Pub_year Sent_text comp_official_name comp_offsetprotein_name organism prot_offset 18455892-1 2008 The first aim of this work was to perform site-directed PEGylation of the enzyme prolidase at sulphydril groups by methoxy-polyethylene glycol-maleimide (Mal-PEG, Mw 5000 Da) in order to obtain a safe conjugation product more stable than the native enzyme. sulphydril 94-104 peptidase D Homo sapiens 81-90