Recombinant proteins L and LG |
| |
Authors: | Vola R Lombardi A Tarditi L Zaccolo M Neri D Björck L Mariani M |
| |
Institution: | (1) Biochemical Oncology Labs., SORIN Biomedica, Saluggia (VC), Italy;(2) Cell Biology Lab., Turin University, Turin, Italy;(3) Cambridge Centre for Protein Engineering, MRC, Cambridge, UK;(4) Medical and Physiological Chemistry Dept., Lund University, Lund, Sweden |
| |
Abstract: | Several bacterial cell wall proteins, like proteins A and G, with valuable affinity for immunoglobulins have been discovered
and are currently employed in immunological techniques. In 1988, protein L, a bacterial cell wall protein with Ig-binding
capacity, was isolated from the anaerobic bacterial speciesPeptostreptococcus magnus. Binding data with immunoglobulin fragments suggested that protein L could selectively bind the variable region of human
kappa light chains. More recently a recombinant LG fusion protein was expressed inE. coli containing four repeated Ig-binding domains of protein L (fragment B1–4) and two IgG Fc-binding protein G domains (fragment
CDC). Recombinant L and LG proteins were tested in the purification of murine monoclonal IgG and their fragments. After affinity-constant
evaluation in different buffer systems, high-pressure affinity-chromatography columns were prepared by coupling the proteins
to Affi-prep 10 resin and tested with eight different murine monoclonal antibodies and their fragments of various isotypes.
Affinity-chromatography experiments confirming radioimmunoassay results showed 75% fragment-binding capacity of protein L
and 100% of protein LG. These results evidenced protein LG as the most powerful Ig-binding tool so far described. Therefore,
application of these proteins may be suggested in the purification of murine immunoglobulins and their fragments, including
the engineered ones. |
| |
Keywords: | Proteins A and G murine antibody fragments Peptostreptococcus magnus |
本文献已被 SpringerLink 等数据库收录! |
|