sentences:  The molecular weight of Protein L purified from the cell walls of "Peptostreptoccus magnus" was first estimated as 95kD by SDS-PAGE in the presence of reducing agent 2-mercaptoethanol, while the molecular weight was determined to 76kD by gel chromotography in the presence of 6 M guanidine HCl.Protein L does not contain any interchain disulfide loops, nor does it consist of disulfide-linked subunits.It is an acidic molecule with a pI of 4.0.