Lysosomal enzyme replacement using alpha 2-macroglobulin as a transport vehicle.
Improvement of the delivery of exogenous enzymes is essential to achieve effective enzyme replacement therapy in lysosomal storage diseases. To test whether alpha 2-macroglobulin, an endogenous plasma protein, could serve as a transport vehicle of therapeutic agents to cells, alpha 2-macroglobulin and acid alpha-glucosidase or alpha-galactosidase A were coupled using two heterobifunctional cross-linking reagents. The alpha-glucosidase-alpha 2-macroglobulin conjugate was internalized and transported into lysosomes of acid alpha-glucosidase-deficient fibroblasts. The enzyme activity was stable after being taken up by the cells. Uptake of the conjugate resulted in the degradation of glycogen accumulated in lysosomes. The alpha-galactosidase A-alpha 2-macroglobulin conjugate was also internalized into the lysosomes of alpha-galactosidase A-deficient fibroblasts. Internalized alpha-galactosidase A-conjugate degraded globotriaosylceramide accumulated in lysosomes. The endocytosis of both conjugate was inhibited by alpha 2-macroglobulin-trypsin complex, indicating that the conjugates were endocytosed by an alpha 2-macroglobulin receptor system. These results showed the usefulness of alpha 2-macroglobulin as a transport vehicle of lysosomal enzymes for effective enzyme replacement.
Tsuji
A
A
Department of Biological Science and Technology, Faculty of Engineering, University of Tokushima.
Oda
R
R
Sakiyama
K
K
Nagamune
H
H
Itoh
K
K
Kase
R
R
Sakuraba
H
H
Suzuki
Y
Y
Matsuda
Y
Y
D000818:Animals; D001692:Biological Transport; D002352:Carrier Proteins / Q000378:metabolism*; D004705:Endocytosis / Q000502:physiology; D005347:Fibroblasts / Q000378:metabolism; D006003:Glycogen / Q000378:metabolism; D006009:Glycogen Storage Disease Type II / Q000378:metabolism / Q000628:therapy; D006868:Hydrolysis; D008247:Lysosomes / Q000201:enzymology*; D013347:Subcellular Fractions / Q000201:enzymology; D013552:Swine; D000519:alpha-Galactosidase / Q000737:chemistry / Q000378:metabolism*; D000520:alpha-Glucosidases / Q000737:chemistry / Q000378:metabolism*; D000511:alpha-Macroglobulins / Q000378:metabolism*
D002352:Carrier Proteins; D000511:alpha-Macroglobulins; D006003:Glycogen; D000520:alpha-Glucosidases; D000519:alpha-Galactosidase