title: Crystallization and preliminary X-ray analysis of a Kunitz-type inhibitor, textilinin-1 from Pseudonaja textilis textilis.
abstract: Textilinin-1 (Txln-1), a Kunitz-type serine protease inhibitor, is a 59-amino-acid polypeptide isolated from the venom of the Australian Common Brown snake Pseudonaja textilis textilis. This molecule has been suggested as an alternative to aprotinin, also a Kunitz-type serine protease inhibitor, for use as an anti-bleeding agent in surgical procedures. Txln-1 shares only 47% amino-acid identity to aprotinin; however, six cysteine residues in the two peptides are in conserved locations. It is therefore expected that the overall fold of these molecules is similar but that they have contrasting surface features. Here, the crystallization of recombinant textilinin-1 (rTxln-1) as the free molecule and in complex with bovine trypsin (229 amino acids) is reported. Two organic solvents, phenol and 1,4-butanediol, were used as additives to facilitate the crystallization of free rTxln-1. Crystals of the rTxln-1-bovine trypsin complex diffracted to 2.0 angstroms resolution, while crystals of free rTxln-1 diffracted to 1.63 angstroms resolution.
authors.affiliation: School of Molecular and Microbial Sciences, University of Queensland, Brisbane 4072, QLD, Australia.
authors.forename: Emma Karin I
authors.initials: EK
authors.lastname: Millers
authors.forename: Paul P
authors.initials: PP
authors.lastname: Masci
authors.forename: Martin F
authors.initials: MF
authors.lastname: Lavin
authors.forename: John
authors.initials: J
authors.lastname: de Jersey
authors.forename: Luke W
authors.initials: LW
authors.lastname: Guddat
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D007611:Aprotinin / Q000737:chemistry*; D002417:Cattle; D003460:Crystallization; D018360:Crystallography, X-Ray; D004546:Elapid Venoms / Q000737:chemistry* / Q000302:isolation & purification; D017815:Elapidae; D005341:Fibrinolysin / Q000037:antagonists & inhibitors; D017386:Sequence Homology, Amino Acid; D014357:Trypsin / Q000737:chemistry / Q000302:isolation & purification; D014961:X-Ray Diffraction
chemical_list: D004546:Elapid Venoms; C413544:textilinin; D007611:Aprotinin; D014357:Trypsin; D005341:Fibrinolysin