title: Crystallization and preliminary X-ray analysis of native and recombinant human bile-salt dependent lipase: strategies for improvement of diffraction quality.
abstract: Human bile-salt dependent lipase (BSDL), secreted into both the digestive tract and human milk, is integral to the effective absorption of dietary lipids. In attempts to obtain crystals suitable for high-resolution X-ray crystallographic studies, various forms of the enzyme have been crystallized, including native and desialidated human milk BSDL and both intact recombinant BSDL and a truncated form lacking the heavily glycosylated C-terminal repeat region. Trigonal crystals of native BSDL, with unit-cell parameters a = b = 90.0, c = 156.1 A, were obtained using 15-20%(w/v) PEG 8000 as precipitant. These crystals diffract to 3.5 A along the unique axis, but to only 5-7 A in orthogonal directions. Crystals of recombinant truncated BSDL grown from 15-20%(w/v) PEG 6000 are orthorhombic, space group P2(1)2(1)2(1), with unit-cell parameters a = 59.2, b = 90.0, c = 107.7 A, and diffract to 2.6 A resolution. These are suitable for structural analysis by X-ray crystallography.
authors.affiliation: Department of Biochemistry, Massey University, Palmerston North, New Zealand.
authors.forename: R L
authors.initials: RL
authors.lastname: Kingston
authors.forename: H M
authors.initials: HM
authors.lastname: Baker
authors.forename: K M
authors.initials: KM
authors.lastname: Loomes
authors.forename: L
authors.initials: L
authors.lastname: Bläckberg
authors.forename: O
authors.initials: O
authors.lastname: Hernell
authors.forename: E N
authors.initials: EN
authors.lastname: Baker
mesh_terms: D003460:Crystallization; D018360:Crystallography, X-Ray; D006031:Glycosylation; D006801:Humans; D008895:Milk, Human / Q000201:enzymology*; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification; D002787:Sterol Esterase / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D011994:Recombinant Proteins; C054784:bile salt-stimulated lipase; D002787:Sterol Esterase