purification of streptococcus pneumoniae type 3 polysaccharides

摘要

methods for reducing or removing protein impurities from a streptococcus pneumoniae cell lysate comprising polysaccharides sorotlpo 3 the present invention relates to improved methods for reducing or removing protein impurities from a lysate or cell centered streptococcus pneumoniae complex comprising polysaccharides serotype 3, involving steps that refer to post-lysis heating or pH adjustment. in certain methods, the lysate is heated for a time and at a temperature sufficient to denature proteins present in the lysate and cause its aggregation and precipitation. in one embodiment, the lysate is heated to at least 60 ° c for at least 30 minutes to cause protein aggregation and precipitation, more particularly about 60 ° c and about 70 ° c for about 30 to about 50 minutes, and even more particularly at about 65 ° C for about 40 minutes. in other methods, the pH of the lysate or center is raised to at least 8.0 to improve filterability, more particularly about 8.0 to 8.4, and even more particularly about 8.2. in additional methods, heating steps and pH adjustment are combined to cause protein aggregation and precipitation, as well as to improve the filtration capacity of lysates or centered. in other methods, the pH of the lysate or center is lowered to about 3.0 to about 5.0 to cause protein aggregation and precipitation. such methods allow the production of substantially purified lysates or sputum containing serotype 3 polysaccharides.