Burton R S
Biol Bull. 1992 Jun;182(3):409-415. doi: 10.2307/1542260.
The free amino acid (FAA) pool of individual Callinectes sapidus megalopas acclimated to 100% seawater averaged over 56% larger than that of 50% seawater acclimated megalopas. Most of the difference was due to a four-fold increase in proline concentration at the higher salinity. In 100% seawater, proline comprises 64% of the total FAA pool in megalopas; this contrasts with the role of proline in adult tissues where it never exceeds 25% of the total FAA pool. Metabolic tracer studies using 14C-glucose and 14C-glutamate as radiolabelled precursors showed that de novo synthesis of proline was very low unless induced by hyperosmotic stress. The induction of the synthetic pathway was inhibited by cycloheximide, a protein synthesis inhibitor. These results suggest that the induction of proline synthesis is regulated by the synthesis of either one of the enzymes catalyzing the three steps in the glutamate to proline pathway or a protein acting to stimulate the activity of one of those enzymes.
适应100%海水的美洲黄道蟹大眼幼体的游离氨基酸（FAA）库平均比适应50%海水的大眼幼体大56%以上。差异的大部分原因是在较高盐度下脯氨酸浓度增加了四倍。在100%海水中，脯氨酸占大眼幼体总FAA库的64%；这与脯氨酸在成体组织中的作用形成对比，在成体组织中脯氨酸从未超过总FAA库的25%。使用14C-葡萄糖和14C-谷氨酸作为放射性标记前体的代谢示踪研究表明，除非受到高渗胁迫诱导，脯氨酸的从头合成非常低。合成途径的诱导受到蛋白质合成抑制剂环己酰亚胺的抑制。这些结果表明，脯氨酸合成的诱导受催化谷氨酸到脯氨酸途径中三个步骤的任何一种酶的合成或一种刺激这些酶之一活性的蛋白质的合成调节。
