Cathepsin B & Synthetic Substrates
lhom at nature.berkeley.edu
Mon May 27 23:04:31 EST 1996
So I've been looking at a viral protease that is homologous to the
cathepsins, and has the substrate specificity of cathepsin B (i.e., it
prefers an Arg 2 aa's N-terminal to the site of cleavage). The researchers
used Z-Arg-Arg-MCA and some other synthetic substrates to demonstrate this.
What sort of puzzles me is why these experiments almost always use
Z-Arg-X-MCA rather than Z-Lys-X-MCA. After all, the crystal structure
suggests a preference for the positive charge of Arg more than, say, its
shape. Any ideas? Is there some esoteric quirk involving difficulty in
Lou Hom >K '93 "If brevity be the soul of wit,
lhom at nature.berkeley.edu play on!"
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