Formation of vitamin D-binding protein-actin and binary and ternary plasma gelsolin-actin complexes in human serum.
After the addition of actin to serum, the binding of actin to serum actin-binding proteins was analyzed by the method of immunoblotting using monospecific antibodies against vitamin D-binding protein (DBP) (group-specific component, Gc), human skeletal actin and human plasma gelsolin. When increasing amounts of globular actin were added to serum, actin bound to DBP preferentially. After exhausting DBP, actin began to bind to plasma gelsolin. When equally increasing amounts of filamentous actin were added to serum, actin was bound to both plasma gelsolin and DBP, and then uncomplexed DBP removed one actin molecule from gelsolin-actin 1:2 complex, resulting in a gelsolin-actin 1:1 complex. These results support the theory that the actin-depolymerizing activity of serum is due to the concerted role of plasma gelsolin and DBP.
Ohsawa
M
M
Department of Legal Medicine, Kurume University School of Medicine, Fukuoka, Japan.
Kimura
H
H
D000199:Actins / Q000097:blood* / Q000302:isolation & purification; D000328:Adult; D001798:Blood Proteins / Q000302:isolation & purification / Q000378:metabolism*; D002135:Calcium-Binding Proteins / Q000097:blood* / Q000302:isolation & purification; D004591:Electrophoresis, Polyacrylamide Gel; D018260:Gelsolin; D006801:Humans; D046911:Macromolecular Substances; D008840:Microfilament Proteins / Q000097:blood* / Q000302:isolation & purification; D013194:Staining and Labeling; D013997:Time Factors; D014809:Vitamin D-Binding Protein / Q000097:blood*
D000199:Actins; D001798:Blood Proteins; D002135:Calcium-Binding Proteins; D018260:Gelsolin; D046911:Macromolecular Substances; D008840:Microfilament Proteins; D014809:Vitamin D-Binding Protein