Niziołek S, Bielawski W, Nalborczyk E
Acta Biochim Pol. 1982;29(3-4):339-47.
The pools of Arg, Gly, His, Ile, Ser, Glu, Leu, Val and Asp were lower during photosynthesis at 1% O2 concentration. At the same time specific radioactivity of a number of amino acids--following 14CO2 incorporation--was different than that at atmospheric O2 concentration. This is probably due to the inhibition of the photorespiratory nitrogen cycle and the resulting NH+4 deficiency. The pattern of response to O2 concentration suggests that in rye plants in the light, all Gly and a part of Ser are synthesized by an O2-sensitive pathway, i.e. via the glycolate pathway, but most of Ser is probably formed from 3-phosphoglycerate (3-PGA) via the O2-insensitive pathway. Changes in the pool size and specific radioactivity after 6 h incubation in darkness suggest that synthesis of Gly is strongly light-dependent, whereas synthesis of Ser was substantial also in darkness. The specific radioactivity of Ala, Asp, Ser and Glu indicates that in darkness those amino acids are formed from a common precursor, i.e. glycolytic 3-PGA, and undergo rapid metabolic turnover.
在1%氧气浓度下进行光合作用时，精氨酸、甘氨酸、组氨酸、异亮氨酸、丝氨酸、谷氨酸、亮氨酸、缬氨酸和天冬氨酸的库含量较低。同时，一些氨基酸在掺入14CO2后的比放射性与大气氧气浓度下的不同。这可能是由于光呼吸氮循环受到抑制以及由此导致的NH4+缺乏。对氧气浓度的响应模式表明，在光照下的黑麦植物中，所有甘氨酸和一部分丝氨酸是通过对氧气敏感的途径合成的，即通过乙醇酸途径，但大部分丝氨酸可能是由3-磷酸甘油酸（3-PGA）通过对氧气不敏感的途径形成的。在黑暗中孵育6小时后库大小和比放射性的变化表明，甘氨酸的合成强烈依赖光照，而丝氨酸的合成在黑暗中也相当可观。丙氨酸、天冬氨酸、丝氨酸和谷氨酸的比放射性表明，在黑暗中这些氨基酸由共同的前体即糖酵解的3-PGA形成，并经历快速的代谢周转。
