Controlled Activation of Protein Rotational Dynamics Using Smart Hydrogel Tethering

• Published in: Journal of the American Chemical Society Vol. 136; no. 38; pp. 13134 - 13137
• Main Authors: Beech, Brenda M, Xiong, Yijia, Boschek, Curt B, Baird, Cheryl L, Bigelow, Diana J, McAteer, Kathleen, Squier, Thomas C
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 24.09.2014
• Subjects: Binding Sites; Calmodulin - chemistry; Hydrogel, Polyethylene Glycol Dimethacrylate - chemistry; Immobilized Proteins - chemistry; Maltose-Binding Proteins - chemistry; Models, Molecular; Nuclear Magnetic Resonance, Biomolecular; Polyethylene Glycols - chemistry; Protein Stability; Skeletal Muscle Myosins - chemistry
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/ja506717v

Stimulus-responsive hydrogel materials that stabilize and control protein dynamics have the potential to enable a range of applications that take advantage of the inherent specificity and catalytic efficiencies of proteins. Here we describe the modular construction of a hydrogel using an engineered calmodulin (CaM) within a poly­(ethylene glycol) (PEG) matrix that involves the reversible tethering of proteins through an engineered CaM-binding sequence. For these measurements, maltose binding protein (MBP) was isotopically labeled with 13C and 15N, permitting dynamic structural measurements using TROSY-HSQC NMR spectroscopy. The protein dynamics is suppressed upon initial formation of hydrogels, with a concomitant increase in protein stability. Relaxation of the hydrogel matrix following transient heating results in enhanced protein dynamics and resolution of substrate-induced large-amplitude domain rearrangements.