POLYPEPTIDE CARTOGRAPHY OF SPIROPLASMA TAIWANENSE

Spiroplasma taiwanense is the first member of the Class Mollicutes to be subjected to polypeptide cartography using computerized image analy sis. The small genome size characteristic of this group was shown to c ode for low numbers of polypeptides when compared to other bacterial s pecies. Silver-stained two-dimensional electrophoresis gels, following separation by either isoelectric focusing and sodium dodecyl sulfate- polyacrylamide gel electrophoresis (ISO-DALT) or nonequilibrium pH gra dient electrophoresis (NEPHGE), were used to create databases from 10 and 6 gels, respectively, for each technique and produced, respectivel y, 263 and 287 replicated spots. Polypeptides were mapped with respect to molecular mass and glyceraldehyde-3-phosphate dehydrogenase carbam ylation standards. Of interest was the unexpectedly high percentage (5 0.2%) of the total normalised optical intensity associated with all 26 3 spots detected by ISO-DALT electrophoresis, having been contributed by just 29 dominant protein spots. These 29 polypeptides are to be giv en priority in microsequencing and microanalysis aimed at their identi fication.