FURTHER STUDIES ON THE ALKYLATION OF NUCLEIC ACIDS AND THEIR CONSTITUENT NUCLEOTIDES

Abstract

Prothidium caused gross loss of motility and clumping of all trypanosomes.Comparison of the findings for trypanosomes with those for other cells previously studied shows that T. Iewi8i iS very similar electrophoretically to freely circulating cells such as lymphocytes and tumour cells.On the other hand, the surface properties of the blood-stream form of T. rhodesiense are different electrophoretically from any other freely circulating cell so far studied.If the surface of these cells does contain carboxyl groups, the previous hypothesis that all cells carrying surface carboxyl groups will be adhesive to phago- cytes will need modification (Bangham & Pethica, 1960).The absence of net charge on the freelycirculating blood-stream form of T. rhodesiense is evidence that van der Waals forces play a very minor role in cell adhesion (Pethica, 1961), although the flagellate motility may adversely influence the adhesion process.SUMMARY 1.Electrophoretic results are presented for Trypanoaoma rhodesiense (blood and culture forms), and for the blood-stream forms of T. congolense, T. equinum, T. lewiisi and T. vivax.2. From a study of the electrophoretic behaviour of trypanosomes at various pH values in the presence and absence of UO+ ions, it is suggested that the surface of the culture form of T. rhodesienre and of the blood-stream form of T. lewi8i is phosphatide in character, whereas that of the blood-stream form of T. rhodesiens8e may be of a polysaccharide or polypeptide nature.3. Several trypanocidal drugs decreased the negative mobility of the blood form of T. Zewi8i and culture form of T. rhode8iense in a manner similar to that found with Ehrlich ascites-tumour cells; they had little effect on the electrophoretic behaviour of the blood form of T. rhode8ier8ee.