2pk4: Difference between revisions

Revision as of 13:16, 4 May 2008

THE REFINED STRUCTURE OF THE EPSILON-AMINOCAPROIC ACID COMPLEX OF HUMAN PLASMINOGEN KRINGLE

OverviewOverview

The crystallographic structure of the plasminogen kringle 4-epsilon-aminocaproic acid (ACA) complex (K4-ACA) has been solved by molecular replacement rotation-translation methods utilizing the refined apo-K4 structure as a search model (Mulichak et al., 1991), and it has been refined to an R value of 0.148 at 2.25-A resolution. The K4-ACA structure consists of two interkringle residues, the kringle along with the ACA ligand, and 106 water molecules. The lysine-binding site has been confirmed to be a relatively open and shallow depression, lined by aromatic rings of Trp62, Phe64, and Trp72, which provide a highly nonpolar environment between doubly charged anionic and cationic centers formed by Asp55/Asp57 and Lys35/Arg71. A zwitterionic ACA ligand molecule is held by hydrogen-bonded ion pair interactions and van der Waals contacts between the charged centers. The lysine-binding site of apo-K4 and K4-ACA have been compared: the rms differences in main-chain and side-chain positions are 0.25 and 0.69 A, respectively, both practically within error of the determinations. The largest deviations in the binding site are due to different crystal packing interactions. Thus, the lysine-binding site appears to be preformed, and lysine binding does not require conformational changes of the host. The results of NMR studies of lysine binding with K4 are correlated with the structure of K4-ACA and agree well.

About this StructureAbout this Structure

2PK4 is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.

ReferenceReference

The refined structure of the epsilon-aminocaproic acid complex of human plasminogen kringle 4., Wu TP, Padmanabhan K, Tulinsky A, Mulichak AM, Biochemistry. 1991 Oct 29;30(43):10589-94. PMID:1657149 Page seeded by OCA on Sun May 4 13:16:45 2008

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OCA

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- {{Structure
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 '''THE REFINED STRUCTURE OF THE EPSILON-AMINOCAPROIC ACID COMPLEX OF HUMAN PLASMINOGEN KRINGLE'''
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 [[Category: Tulinsky, A.]]
 [[Category: Wu, T P.]]
-[[Category: hydrolase(serine protease)]]
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun May  4 13:16:45 2008''
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Mon Mar 31 04:36:59 2008''