The assumption that structural or sequential homology between enzymes implies functional homology is a common misconception. Through in-depth structural and kinetic analysis, we are now beginning to understand the minute differences in primary structure that can alter the function of an enzyme completely. Alternative splicing is one method for which the activity of an enzyme can be controlled, simply by altering its length. Arylalkylamine N-acetyltransferase A (AANATA) in D. melanogaster, which catalyzes the N-acetylation of biogenic amines, has multiple splicoforms – alternatively spliced enzyme isoforms – with differing tissue distribution. As demonstrated here, AANAT1 from Tribolium castaneum is another such enzyme with multiple splicoforms. A screening assay was developed and utilized to determine that, despite only a 35 amino acid truncation, the shortened form of TcAANAT1 is a more active form of the enzyme. This implies regulation of enzyme metabolic activity via alternative splicing.

酶之间的结构或顺序同源性意味着功能同源性的假设是一种常见的误解。通过深入的结构和动力学分析，我们现在开始了解可以完全改变酶功能的一级结构的微小差异。选择性剪接是一种可以通过改变酶的长度来控制酶活性的方法。D. melanogaster 中的芳基烷基胺N-乙酰转移酶 A (AANATA)催化生物胺的N-乙酰化，具有多种剪接形式 - 或者剪接酶异构体 - 具有不同的组织分布。如此处所示，来自Tribolium castaneum 的AANAT1是另一种具有多种剪接形式的酶。开发并使用了一种筛选试验来确定，尽管只有 35 个氨基酸被截断，但Tc AANAT1的缩短形式是该酶的一种更具活性的形式。这意味着通过选择性剪接调节酶代谢活性。