The occurrence of free D-alanine and an alanine racemase activity in Leishmania amazonensis.
Free D-amino acids are implicated in several biological functions. This study examined the presence of D-alanine in Leishmania amazonensis. Measuring chiral amino acid content by high-performance liquid chromatography we detected a significant amount of free D-alanine in promastigotes of these parasites. D-alanine accounts for 8.9% of total free alanine and is found primarily in the soluble fraction. Specific racemization of L-alanine to D-alanine was detected in cell lysates and this enzyme activity was inhibited by D-cycloserine, an alanine racemase inhibitor. Furthermore, we were able to decrease this pool of D-amino acid by treating our cultures with D-cycloserine. We demonstrate for the first time the existence of a significant amount of free D-alanine in L. amazonensis and an alanine racemase activity present in cell lysates. The restriction of D-alanine to bacteria, some fungi and now in L. amazonensis opens a new perspective on treatment of diseases caused by these microorganisms.
Departamento de Anatomia, ICB, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
Rogério
R
Panizzutti
Milane
M
de Souza Leite
Carla M
CM
Pinheiro
José Roberto
JR
Meyer-Fernandes
D000409:Alanine / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism*; D000411:Alanine Racemase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000818:Animals; D002478:Cells, Cultured; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D003523:Cycloserine / Q000494:pharmacology; D007894:Leishmania mexicana / Q000737:chemistry* / Q000201:enzymology*; D008018:Life Cycle Stages; D013997:Time Factors
D003523:Cycloserine; D000411:Alanine Racemase; D000409:Alanine