 |
|
Title
|
|
The 1.6 A structure of Kunitz-type domain from the alpha 3 chain of human type VI collagen.
|
|
|
Authors
|
|
B.Arnoux,
K.Mérigeau,
P.Saludjian,
F.Norris,
K.Norris,
S.Bjørn,
O.Olsen,
L.Petersen,
A.Ducruix.
|
|
|
Ref.
|
|
J Mol Biol, 1995,
246,
609-617.
|
|
|
PubMed id
|
|
|
|
|
|
Abstract
|
|
|
The C-terminal Kunitz-type domain from the alpha 3 chain of human type VI
collagen (C5), a single 58 amino acid residue chain with three disulfide
bridges, was cloned, expressed and crystallized in a monoclonic form, space
group P2(1), with a = 25.7 A, b = 38.2 A, c = 28.8 A and beta = 109 degrees. The
structure was resolved by molecular replacement, using Alzheimer's protein
precursor inhibitor and bovine pancreatic trypsin inhibitor three-dimensional
structures as search models. The molecule with one sulfate ion and 43 associated
water molecules was refined by XPLOR to an R-factor of 18.9% at 1.6 A. The
molecule was not degraded by trypsin and did not inhibit trypsin or tested
serine proteases. As opposed to the other Kunitz family members, C5 demonstrates
left-handed chirality of the Cys14-Cys38 disulfide bond. Inversion of the Thr13
carbonyl and bulky side-chains at the interface with trypsin in a model of the
C5-trypsin complex may explain the lack of inhibition of trypsin.
|
|
|
|