2pk4
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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.
DiseaseDisease
Known diseases associated with this structure: Conjunctivitis, ligneous OMIM:[173350], Plasminogen Tochigi disease OMIM:[173350], Plasminogen deficiency, types I and II OMIM:[173350], Thrombophilia, dysplasminogenemic OMIM:[173350]
About this StructureAbout this Structure
2PK4 is a Single protein structure of sequence from Homo sapiens with ACA as ligand. 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
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