• Record: found
  • Abstract: found
  • Article: not found

Phospholipase A2 is a major component of the salt-extractable pool of matrix proteins in adult human articular cartilage.

Arthritis and Rheumatism

Adolescent, enzymology, Synovial Fluid, Phospholipases A2, physiology, genetics, analysis, Phospholipases A, Molecular Sequence Data, Middle Aged, Humans, Extracellular Matrix Proteins, Electrophoresis, Polyacrylamide Gel, pathology, chemistry, Cartilage, Articular, physiopathology, Arthritis, Rheumatoid, Amino Acid Sequence

Read this article at

      There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.


      Adult human articular cartilage contains a component with an apparent molecular weight of 16 kd, which is extractable with high ionic strength buffers. This protein, which, in addition to lysozyme, is one of the most prominent components in salt extracts of adult cartilage, is not detectable in cartilage from newborns. We performed N-terminal sequence analysis to identify the protein. The amino acid sequence obtained for the first 20 residues was identical to that reported for phospholipase A2 (PLA2) from human placenta and human synovial cells. The extractable PLA2 was found to be active. The lack of PLA2 in salt extracts from newborn cartilage observed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis was confirmed by the very low levels of PLA2 activity detectable in these preparations. PLA2 was clearly present in cartilage extracts from an 18-year-old subject and a 19-year-old subject, suggesting that its accumulation begins at some stage during the adolescent growth period. The enzyme does not appear to be released from cartilage matrix under normal physiologic conditions, and it is possible that the accumulation of PLA2 in maturing cartilage is a result of the decreased matrix turnover associated with the termination of skeletal growth. Whether PLA2 is active in the cartilage matrix, its precise localization, and its effects on the resident chondrocytes remain to be determined.

      Related collections

      Author and article information



      Comment on this article