Structural Characterization of Acylimine-Containing Blue and Red Chromophores in mTagBFP and TagRFP Fluorescent Proteins

详细信息    查看全文

• 作者：Oksana M. Subach ; Vladimir N. Malashkevich ; Wendy D. Zencheck ; Kateryna S. Morozova ; Kiryl D. Piatkevich ; Steven C. Almo ; Vladislav V. Verkhusha
• 刊名：Chemistry & Biology
• 出版年：2010
• 出版时间：23 April 2010
• 年：2010
• 卷：17
• 期：4
• 页码：333-341
• 全文大小：618 K

文摘

Summary

We determined the 2.2 Å crystal structures of the red fluorescent protein TagRFP and its derivative, the blue fluorescent protein mTagBFP. The crystallographic analysis is consistent with a model in which TagRFP has the trans coplanar anionic chromophore with the conjugated π-electron system, similar to that of DsRed-like chromophores. Refined conformation of mTagBFP suggests the presence of an N-acylimine functionality in its chromophore and single C^α-C^β bond in the Tyr64 side chain. Mass spectrum of mTagBFP chromophore-bearing peptide indicates a loss of 20 Da upon maturation, whereas tandem mass spectrometry reveals that the C^α-N bond in Leu63 is oxidized. These data indicate that mTagBFP has a new type of the chromophore, N-[(5-hydroxy-1H-imidazole-2-yl)methylidene]acetamide. We propose a chemical mechanism in which the DsRed-like chromophore is formed via the mTagBFP-like blue intermediate.