Bonay P, Cohen B E
Biochim Biophys Acta. 1983 Jun 10;731(2):222-8. doi: 10.1016/0005-2736(83)90012-3.
Neutral amino acid transport was investigated in Leishmania promastigotes. Proline and alanine transport occur against their concentration gradient although there is a very rapid (40% at 30 min) conversion of proline to alanine. Uptake of these amino acids occurs by a sodium-independent route which is completely eliminated by addition of CCCP or KCN. Km values for proline and alanine are 80 microM and 63 microM with Vmax values of 6.4 and 7.2 nmol/min per mg dry weight, respectively. Countertransport of proline, alanine and phenylalanine was measured by loading the cells with a variety of neutral amino acids and proline analogs, followed by CCCP addition. The effect of aminooxyacetic acid, an inhibitor of alanine aminotransferase (EC 2.6.1.2), on proline and alanine countertransport was also examined. The results obtained are consistent with the presence of at least two systems for neutral amino acid transport in Leishmania promastigotes.
对利什曼原虫前鞭毛体中的中性氨基酸转运进行了研究。脯氨酸和丙氨酸的转运是逆着它们的浓度梯度进行的，尽管脯氨酸会非常快速地（30分钟时为40%）转化为丙氨酸。这些氨基酸的摄取通过一条不依赖钠的途径进行，添加羰基氰间氯苯腙（CCCP）或氰化钾（KCN）可完全消除该途径。脯氨酸和丙氨酸的米氏常数（Km）分别为80微摩尔和63微摩尔，每毫克干重的最大反应速度（Vmax）值分别为6.4和7.2纳摩尔/分钟。通过用多种中性氨基酸和脯氨酸类似物加载细胞，然后添加CCCP来测量脯氨酸、丙氨酸和苯丙氨酸的反向转运。还研究了丙氨酸转氨酶（EC 2.6.1.2）的抑制剂氨基氧乙酸对脯氨酸和丙氨酸反向转运的影响。所获得的结果与利什曼原虫前鞭毛体中至少存在两种中性氨基酸转运系统一致。
