Details

Autor(en) / Beteiligte

• Krebs, Joseph F
• Srinivasan, Anu
• Wong, Angela M
• Tomaselli, Kevin J
• Fritz, Lawrence C
• Wu, Joe C

Titel

Heavy Membrane-Associated Caspase 3:  Identification, Isolation, and Characterization

Ist Teil von

• Biochemistry (Easton), 2000-12, Vol.39 (51), p.16056-16063

Ort / Verlag

United States: American Chemical Society

Erscheinungsjahr

2000

Quelle

MEDLINE

Beschreibungen/Notizen

• Heavy membrane preparations from 697 lymphoblastoid cells contain a tightly bound caspase zymogen. This heavy membrane-bound procaspase can be efficiently liberated from membrane preparations using detergents. Alternatively, the procaspase can be rapidly processed and activated from membrane preparations by caspase-1 without detergents. The activated caspase-3 was purified using affinity chromatography and characterized by amino acid sequencing and inhibitor specificity analysis. The sequence indicates that this heavy membrane bound caspase is caspase-3. The kinetic properties and inhibitor binding specificity also show that this purified caspase is enzymologically indistinguishable from cytoplasmic or recombinant caspase-3. However, the N-termini of activated heavy membrane-bound and cytoplasmic caspase-3 are slightly different; peptide sequencing data indicate that the heavy membrane caspase-3 begins at Lys 14, whereas the cytoplasmic enzyme begins at Ser 10. Implications of this structural difference are discussed.