Human liver cathepsin D. Purification, crystallization and preliminary X-ray diffraction analysis of a lysosomal enzyme

Autor: S, Gulnik, E T, Baldwin, N, Tarasova, J, Erickson
Rok vydání: 1992
Předmět:
Zdroj: Journal of molecular biology. 227(1)
ISSN: 0022-2836
Popis: The two-chain form of active cathepsin D, a glycosylated, lysosomal aspartic proteinase, has been isolated from human liver. Isoelectric focusing revealed two major species of enzyme that differed by approximately 0.2 pI unit. Crystals suitable for X-ray diffraction analysis were prepared from acidic solutions using precipitation with ammonium sulfate. The hexagonal crystals diffracted X-rays to beyond 3.1 A resolution and belonged to space group P6(1) (or P6(5)) with cell constants a = b = 125.9 A, c = 104.1 A, gamma = 120.0 degrees. The crystals likely contain two molecules in the asymmetric unit, giving a solvent content of 56% (v/w). Biochemical analysis of crystals indicated that both isoforms were present in approximately equimolar proportions. Full structure determination of the enzyme is underway.
Databáze: OpenAIRE