Dual-site recognition of different extracellular matrix components by anti-angiogenic/neurotrophic serpin, PEDF.
Pigment epithelium-derived factor (PEDF), a member of the serine protease inhibitor (serpin) superfamily, possesses anti-angiogenic and neurotrophic activities. PEDF has been reported to bind to extracellular matrix (ECM) components such as collagens and glycosaminoglycans (GAGs). In this study, to determine the binding sites for collagens and GAGs, we analyzed the interaction of recombinant mouse PEDF (rPEDF) with collagen I and heparin. By utilizing residue-specific chemical modification and site-directed mutagenesis techniques, we revealed that the acidic amino acid residues on PEDF (Asp(255), Asp(257), and Asp(299)) are critical to collagen binding, and three clustered basic amino acid residues (Arg(145), Lys(146), and Arg(148)) are necessary for heparin binding. Mapping of these residues on the crystal structure of human PEDF (Simonovic, M., Gettins, P. G. W., and Volz, K. (2001) Proc. Natl. Acad. Sci. U.S.A. 98, 11131-11135) demonstrated that the collagen-binding site is oriented toward the opposite side of the highly basic surface where the heparin-binding site is localized. These results indicate that PEDF possesses dual binding sites for different ECM components, and this unique localization of ECM-binding sites implies that the binding to ECM components could regulate PEDF activities.
Yasui
Norihisa
N
Department of Biological Science and Technology, Faculty of Engineering, The University of Tokushima, Tokushima 770-8506, Japan.
Mori
Terumi
T
Morito
Daisuke
D
Matsushita
Osamu
O
Kourai
Hiroki
H
Nagata
Kazuhiro
K
Koide
Takaki
T
D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002942:Circular Dichroism; D017931:DNA Primers; D016326:Extracellular Matrix Proteins / Q000378:metabolism*; D005136:Eye Proteins; D051379:Mice; D008958:Models, Molecular; D016297:Mutagenesis, Site-Directed; D018919:Neovascularization, Physiologic / Q000502:physiology*; D009414:Nerve Growth Factors; D011506:Proteins / Q000737:chemistry / Q000378:metabolism* / Q000502:physiology; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D015843:Serpins / Q000737:chemistry / Q000378:metabolism* / Q000502:physiology; D000099174:Pigment Epithelium-Derived Factor
D017931:DNA Primers; D016326:Extracellular Matrix Proteins; D005136:Eye Proteins; D009414:Nerve Growth Factors; D011506:Proteins; D011994:Recombinant Proteins; D015843:Serpins; D000099174:Pigment Epithelium-Derived Factor