半胱氨酸殘跡在蛋白的催化或調(diào)控點上經(jīng)常是活躍的，這是由于它們硫醇側(cè)鏈?zhǔn)菢O為親核的,。側(cè)鏈活性因局部蛋白微環(huán)境的不同而有很大差別，但被稱為“定量活性分析”的一種新方法（該方法將基于活性的小分子探針與質(zhì)譜結(jié)合在一起）使得測定半胱氨酸殘跡的內(nèi)在活性成為可能,。在幾種功能未知的蛋白中識別出了活性超強的半胱氨酸,，其中包括在所有真核生物中都保留了下來的殘跡,，它是酵母的存活能力所必需的，也涉及鐵-硫蛋白的生物生成,。（生物谷Bioon.com）
生物谷推薦原文出處：
Nature doi:10.1038/nature09472
Quantitative reactivity profiling predicts functional cysteines in proteomes
Eranthie Weerapana,Chu Wang,Gabriel M. Simon,Florian Richter,Sagar Khare,Myles B. D. Dillon,Daniel A. Bachovchin,Kerri Mowen,David Baker& Benjamin F. Cravatt
Cysteine is the most intrinsically nucleophilic amino acid in proteins, where its reactivity is tuned to perform diverse biochemical functions. The absence of a consensus sequence that defines functional cysteines in proteins has hindered their discovery and characterization. Here we describe a proteomics method to profile quantitatively the intrinsic reactivity of cysteine residues en masse directly in native biological systems. Hyper-reactivity was a rare feature among cysteines and it was found to specify a wide range of activities, including nucleophilic and reductive catalysis and sites of oxidative modification. Hyper-reactive cysteines were identified in several proteins of uncharacterized function, including a residue conserved across eukaryotic phylogeny that we show is required for yeast viability and is involved in iron-sulphur protein biogenesis. We also demonstrate that quantitative reactivity profiling can form the basis for screening and functional assignment of cysteines in computationally designed proteins, where it discriminated catalytically active from inactive cysteine hydrolase designs
