Analysis of polypeptides of mutants of Mycoplasma pneumoniae that lack the ability to haemadsorb.

Haemadsorption-negative mutants of Mycoplasma pneumoniae were isolated which varied in their capacity to adsorb erythrocytes of various animal species suggesting adherence to erythrocytes is mediated by different binding mechanisms. Trypsin treatment of the wild-type strain resulted in loss of haemadsorbing activity; several polypeptides, some of which regenerated with haemadsorbing activity following further incubation, were also trypsin sensitive. The haemadsorption-negative mutants could be divided into two groups according to their polypeptide pattern. In the first group (11 mutants) the PAGE pattern was identical to that of the wild-type strain. The second group comprised 7 mutants which differed from the wild-type by lack of one or more polypeptides with molecular weights of 190 000, 90 000 or 40 000. During growth attachment to glass was weak or absent in the mutants. Surface hydrophobicity as measured by hydrophobic-interaction chromatography was nearly comparable in mutants and parent strain.