In:
European Journal of Biochemistry, Wiley, Vol. 199, No. 3 ( 1991-08), p. 601-607
Abstract:
One‐ and two‐dimensional NMR studies were performed on the complexes of porcine pancreatic phospholipase A 2 with substrate analogs bound to a micellar lipid‐water interface of fully deuterated dodecylphosphocholine. The interactions between the inhibitor and the enzyme were localized by comparison of the two‐dimensional NOE spectra recorded for the enzyme‐inhibitor complex using both protonated and selectively deuterated inhibitors. These experiments led us to the following conclusions for the phospholipase‐A 2 ‐micelle complex: (i) the 38‐kDa phospholipase A 2 complex gives NMR spectra with relatively narrow lines, which is indicative of high mobility of the enzyme; (ii) the residues Ala1, Trp3, Phe63 and Tyr69 located in the interface recognition site, as well as Phe22, Tyr75, Phe106 and Tyr111 are involved in the micelle‐binding process; (iii) when present on the micelle, phospholipase A 2 is stereospecific for the inhibitor binding; (iv) the inhibitor, ( R )‐dodecyl‐2‐aminohexanol‐1‐phosphoglycol, binds stoichiometrically to phospholipase A 2 with high affinity ( K d ≤ 10 μM); (v) the inhibitor binds in the active site of the enzyme, which is evidenced by large chemical‐shift differences for Phe5, Ile9, Phe22, His48, Tyr52 and Phe106; (vi) the acyl chain of the inhibitor makes hydrophobic contacts ( 〈 0.4 nm) near Phe5, Ile9, Phe22 and Phe106. Comparison of our results on the enzyme‐inhibitor‐micelle ternary complex with the crystal structure of the enzyme‐inhibitor complex [Thunnissen, M. M. G. M., AB, E., Kalk, K. H., Drenth, J., Dijkstra, B. W., Kuipers, O. P., Dijkman, R., de Haas, G. H. & Verheij, H. M. (1990) Nature 347 , 689–691] shows that the mode of inhibitor binding is similar.
Type of Medium:
Online Resource
ISSN:
0014-2956
,
1432-1033
DOI:
10.1111/ejb.1991.199.issue-3
DOI:
10.1111/j.1432-1033.1991.tb16160.x
Language:
English
Publisher:
Wiley
Publication Date:
1991
detail.hit.zdb_id:
1398347-7
detail.hit.zdb_id:
2172518-4
SSG:
12
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