Direct visualization of affected collagen molecules synthesized by cultured fibroblasts from an osteogenesis imperfecta patient.
Human skin fibroblasts obtained from normal controls and a patient with osteogenesis imperfecta were cultured in the presence of ascorbic acid 2-phosphate, a long-acting vitamin C derivative. Crude collagen samples extracted from the cell layer were made to form lateral aggregates of collagen molecules, segment-long-spacing crystallites. Under the electron microscope, normal and abnormal crystallites of type I collagen were identified with the patient's collagen. While the carboxyl-terminal half of the abnormal crystallite was tightly packed, the amino-terminal half was loose and spreading, indicating the site of abnormality in the amino-terminal half of one of type I collagen alpha chains. The method is simple and useful to detect abnormal collagen and to predict the site of mutation.
Kobayashi
K
K
Department of Anatomy, Nagoya University School of Medicine, Japan.
Hata
R
R
Nagai
S
S
Niwa
J
J
Hoshino
T
T
D000328:Adult; D000595:Amino Acid Sequence; D002478:Cells, Cultured; D003094:Collagen / Q000096:biosynthesis / Q000648:ultrastructure*; D005260:Female; D005347:Fibroblasts / Q000378:metabolism; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D008854:Microscopy, Electron; D009154:Mutation; D010013:Osteogenesis Imperfecta / Q000378:metabolism*; D011487:Protein Conformation; D012016:Reference Values; D012867:Skin / Q000378:metabolism*
D003094:Collagen