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PDBsum entry 1bwp
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References listed in PDB file
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Key reference
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Title
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Probing the substrate specificity of the intracellular brain platelet-Activating factor acetylhydrolase.
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Authors
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Y.S.Ho,
P.J.Sheffield,
J.Masuyama,
H.Arai,
J.Li,
J.Aoki,
K.Inoue,
U.Derewenda,
Z.S.Derewenda.
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Ref.
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Protein Eng, 1999,
12,
693-700.
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PubMed id
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Note In the PDB file this reference is
annotated as "TO BE PUBLISHED".
The citation details given above were identified by an automated
search of PubMed on title and author
names, giving a
perfect match.
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Abstract
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Platelet-activating factor acetylhydrolases (PAF-AHs) are unique PLA2s which
hydrolyze the sn-2 ester linkage in PAF-like phospholipids with a marked
preference for very short acyl chains, typically acetyl. The recent solution of
the crystal structure of the alpha(1) catalytic subunit of isoform Ib of bovine
brain intracellular PAF-AH at 1.7 A resolution paved the way for a detailed
examination of the molecular basis of substrate specificity in this enzyme. The
crystal structure suggests that the side chains of Thr103, Leu48 and Leu194 are
involved in substrate recognition. Three single site mutants (L48A, T103S and
L194A) were overexpressed and their structures were solved to 2.3 A resolution
or better by X-ray diffraction methods. Enzyme kinetics showed that, compared
with wild-type protein, all three mutants have higher relative activity against
phospholipids with sn-2 acyl chains longer than an acetyl. However, for each of
the mutants we observed an unexpected and substantial reduction in the V(max) of
the reaction. These results are consistent with the model in which residues
Leu48, Thr103 and Leu194 indeed contribute to substrate specificity and in
addition suggest that the integrity of the specificity pocket is critical for
the expression of full catalytic function, thus conferring very high substrate
selectivity on the enzyme.
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Secondary reference #1
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Title
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Brain acetylhydrolase that inactivates platelet-Activating factor is a g-Protein-Like trimer.
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Authors
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Y.S.Ho,
L.Swenson,
U.Derewenda,
L.Serre,
Y.Wei,
Z.Dauter,
M.Hattori,
T.Adachi,
J.Aoki,
H.Arai,
K.Inoue,
Z.S.Derewenda.
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Ref.
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Nature, 1997,
385,
89-93.
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PubMed id
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