title: Structurally unique recombinant Kazal-type proteinase inhibitor retains activity when terminally extended and glycosylated.
abstract: Recombinant derivatives of the Kazal-type serine proteinase inhibitor GmSPI2 (36 amino acid residues), which is a component of insect silk, were prepared in the expression vector Pichia pastoris. The rhSPI2 had a C-terminal hexahistidine tag attached to the GmSPI2 sequence, rtSPI2 was extended with GluAlaAla at the N-terminus, and rfSPI2 included this N-terminal extension and a C-terminal tail of 22 residues (myc epitope and hexahistidine). A portion of the secreted rfSI2 was O-glycosylated with a trimannosyl or hexamannosyl. The native inhibitor was active slightly on trypsin and highly on subtilisin and proteinase K. The extended C-terminus in rhSPI2 and rfSPI2 enhanced activity on the two latter enzymes and rendered rfSPI2 active on elastase and pronase, but abolished the inhibition of trypsin. The glycosylation of rfSPI2 reduced its inhibitory activity to a level comparable with the native inhibitor. The rtSPI2 with tripeptide extension at the N-terminus and no C-terminal modification was clearly less active than the native inhibitor. None of the tested compounds inhibited alpha-chymotrypsin and the non-serine proteinases.
authors.affiliation: Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5a, 02-106 Warszawa, Poland.
authors.forename: Barbara
authors.initials: B
authors.lastname: Kludkiewicz
authors.forename: Dalibor
authors.initials: D
authors.lastname: Kodrík
authors.forename: Krystyna
authors.initials: K
authors.lastname: Grzelak
authors.forename: Xavier
authors.initials: X
authors.lastname: Nirmala
authors.forename: Frantisek
authors.initials: F
authors.lastname: Sehnal
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015870:Gene Expression; D006031:Glycosylation; D019476:Insect Proteins / Q000737:chemistry* / Q000235:genetics; D008969:Molecular Sequence Data; D009036:Moths / Q000737:chemistry / Q000235:genetics; D010843:Pichia / Q000235:genetics; D011499:Protein Processing, Post-Translational / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D012697:Serine Endopeptidases / Q000737:chemistry*; D015842:Serine Proteinase Inhibitors / Q000737:chemistry* / Q000235:genetics; D014359:Trypsin Inhibitor, Kazal Pancreatic / Q000737:chemistry / Q000235:genetics
chemical_list: D019476:Insect Proteins; D011993:Recombinant Fusion Proteins; D015842:Serine Proteinase Inhibitors; D014359:Trypsin Inhibitor, Kazal Pancreatic; D012697:Serine Endopeptidases