Open AccessCharacterization of native laminin from bovine kidney and comparison with other laminin variants
Author(s) -
LINDBLOM Anders,
MARSH Tracey,
FAUSER Charlotte,
ENGEL Jürgen,
PAULSSON Mats
Publication year - 1994
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1994.tb19950.x
Subject(s) - laminin , computational biology , biology , microbiology and biotechnology , extracellular matrix
A comprehensive characterization of laminin isoforms requires access to native preparations of laminins of a defined subunit composition. For this purpose an optimized isolation procedure was developed and shown to be broadly applicable to normal mammalian tissues. The protocol does in addition yield side fractions highly enriched in collagens XII and XIV. The major laminin purified from bovine kidney is indistinguishable from mouse Engelbreth‐Holm‐Swarm (EHS) tumor laminin in electron microscopy, but contains an A chain that migrates in a position intermediate to the Ae and the Am chains on SDS/PAGE. Antisera raised against mouse EHS‐tumor laminin crossreact with B chains, but not with the A chain, of kidney laminin. Further, this A chain is not recognized by antisera raised against the Am chain. Laminins from heart and kidney both contain a significant subpopulation with a 190‐kDa polypeptide identified as the B1s chain. The Am‐containing laminins from heart and placenta differ morphologically from the Ae‐containing EHS laminin in having one short arm that does not have the characteristic globule‐rod‐globule appearance. Further, the Am‐containing laminins show a significantly higher thermal stability of the coiled‐coil α‐helical region in the long arm than does Ae‐containing EHS laminin, indicating that certain combinations of laminin chains interact more strongly than others.