Open AccessBinding Properties and Protease Stability of Recombinant Human Nidogen
Author(s) -
Mayer Ulrike,
Zimmermann Katrin,
Mann Karlheinz,
Reinhardt Dieter,
Timpl Rupert,
Nischt Roswitha
Publication year - 1995
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1995.0681p.x
Subject(s) - perlecan , recombinant dna , glycosylation , laminin , biochemistry , proteases , proteolysis , biology , heparan sulfate , microbiology and biotechnology , chemistry , enzyme , extracellular matrix , glycosaminoglycan , gene
Recombinant human nidogen was obtained from transfected kidney cell clones as a 150‐kDa protein with a three‐globule structure. It was modified by sulfation and O ‐glycosylation and a lower level of N‐ glycosylation than mouse nidogen. Recombinant nidogens of both species were, however, indistinguishable in their affinities for laminin‐1 and a recombinant laminin γ1 chain fragment and showed a similar binding to collagen IV and the heparan sulfate proteoglycan perlecan. The two nidogens were also equivalent in the promotion of ternary complex formation between these ligands, indicating that this function has been conserved during mammalian evolution. Fewer zinc‐binding sites could be identified in human nidogen and correlated with a lower capacity of zinc to prevent binding to laminin and collagen IV. Most remarkable was the greater sensitivity of human nidogen to endogenous proteolysis in cell culture, yielding fragments of 90–145 kDa. Studies with several exogenous proteases, including thrombin and leucocyte elastase, showed lack of stability of the N‐terminal globular domain G1 in contrast to what was found for mouse nidogen. Since such degradation could be important for basement membrane remodelling, this difference between human and mouse may be biologically significant.