| First Author | Sasaki T | Year | 2002 |
| Journal | Eur J Biochem | Volume | 269 |
| Issue | 2 | Pages | 431-42 |
| PubMed ID | 11856301 | Mgi Jnum | J:74545 |
| Mgi Id | MGI:2158604 | Doi | 10.1046/j.0014-2956.2001.02663.x |
| Citation | Sasaki T, et al. (2002) Domain IV of mouse laminin beta1 and beta2 chains. Eur J Biochem 269(2):431-42 |
| abstractText | Domain IV, consisting of about 230 residues, represents a particular protein module so far found only in laminin beta1 and beta2 chains. Both domains were obtained by recombinant production in mammalian cells. They showed a globular structure, as expected from electron microscopic examination of laminins. Fragment beta1IV was obtained as a monomer and a disulfide-bonded dimer, and both were modified to approximately 50% by a single chondroitin sulfate chain attached to Ser721 of an SGD consensus sequence. Dimerization is caused by an odd number of cysteines, with three of them having a partial thiol character. Whether both modifications also occur in tissue forms of laminin remains to be established. Fragment beta2IV was only obtained as a monomer, as it lacked one crucial cysteine and the SGD sequence. It required, however, the presence of two adjacent LE modules for proper folding. Polyclonal antibodies raised against both fragments showed no cross-reaction with each other and allowed establishment of beta chain-specific radioimmunoassays and light and electron microscopic immunostaining of tissues. This demonstrated a 5-25-fold lower content of beta2 compared with beta1 chains in various tissue extracts of adult mice. Tissues derived from beta2-deficient mice failed to react with the beta2-specific antibodies but showed a twofold higher content of beta1 than heterozygotes. The antibodies to beta2 showed broader tissue staining than reported previously, including in particular a distinct reaction with the extrasynaptic endomysium of skeletal muscle. Immunogold staining localized both beta chains primarily to basement membranes of kidney, muscle and various other tissues. |
