研究人员用 AI 设计可切割其他蛋白的蛋白酶
Researchers use AI to design proteins that cut up other proteins
研究人员利用基于 AI 的蛋白设计工具，保留两类蛋白酶催化核心并替换蛋白其余部分，设计出可定向将特定蛋白切成两半的酶。他们通过切割与神经疾病相关的蛋白验证了这些酶的有效性，相当于跳过了蛋白酶自然多样化的演化过程。肽键本身极为稳定，估计半衰期达数百年，而生物体演化出多种催化肽键断裂的方式，形成众多专门的蛋白消化酶。
A protein is a chain of amino acids held together by what are called peptide bonds. On their own, those bonds are extremely stable; they're estimated to have a half-life of several hundred years. But in Earth's environment, most proteins don't last nearly that long. That's because organisms have evolved a handful of ways to catalyze the break-up of peptide bonds, which have diversified into countless specialized protein-digesting enzymes. Proteases are everywhere and generally make short work of any proteins that find their way into the environment.
Now, researchers have basically short-circuited the diversification process, using AI-based protein design tools to take the catalytic core of two types of protease and replace the entire rest of the protein. The resulting enzymes could be tuned to cut specific proteins in half, and the researchers demonstrated their effectiveness by using them to cut proteins associated with neurological diseases.
Cutting proteins
The basic peptide bond isn't especially interesting-looking—it's what you get when you link an amino group to an acid, releasing a water molecule in the process. As their name implies, amino acids have both an amino and an acid group, allowing them to form peptide bonds on two sides of the amino acid. This is critical for building up the long chains found in proteins. (The amino acids also have side chains with distinctive chemistry, which gives a backbone specific properties.)
来源：Ars Technica · AI · arstechnica.com