Distribution of charged pterins in nonmethanogenic archaebacteria

Abstract

Pterin content was surveyed in nine species of nonmethanogenic archaebacteria comprised of six species of halobacteria, two species of Sulfolobus, and one specie of Thermoplasma. The results indicated the presence of the sulfate-containing dimeric pterin sulfohalopterin-2 in three species of halobacteria, “Halobacterium marismortui”, halobacterial strain GN-1, and Halobacterium volcanii. The phosphate-containing dimeric pterin phosphohalopterin-1 was present in three other species of halobacteria, Halobacterium salinarium, Halobacterium halobium, and Halococcus morrhuae. Evidence is presented that these halopterins exist in the halobacteria as tetrahydropterin derivatives. A positively charged monomeric pterin, solfapterin (erythro-neopterin-3′-D-2-deoxy-2-aminoglucopyranoside), was found to be present in Sulfolobus solfataricus and a negatively charged pterin was induced when S. solfataricus was grown in a medium containing homogentisic acid (2,5-dihydroxyphenylacetic acid). This negatively charged pterin was not present when the cells were grown in the normal medium. Another positively charged pterin found in Thermoplasma was determined to be different from solfapterin based on its paper electrophoresis properties. Uncharged pterins were also identified in all of these bacteria, however, no attempt was made to elucidate the structure of these uncharged pterins. Pterin content was found to vary in the different bacteria and to depend on the conditions under which the cells were grown.