title: Engineering proteins with enhanced mechanical stability by force-specific sequence motifs.
abstract: Use of atomic force microscopy (AFM) has recently led to a better understanding of the molecular mechanisms of the unfolding process by mechanical forces; however, the rational design of novel proteins with specific mechanical strength remains challenging. We have approached this problem from a new perspective that generates linear physical-chemical properties (PCP) motifs from a limited AFM data set. Guided by our linear sequence analysis, we designed and analyzed four new mutants of the titin I1 domain with the goal of increasing the domain's mechanical strength. All four mutants could be cloned and expressed as soluble proteins. AFM data indicate that at least two of the mutants have increased molecular mechanical strength. This observation suggests that the PCP method is useful to graft sequences specific for high mechanical stability to weak proteins to increase their mechanical stability, and represents an additional tool in the design of novel proteins besides steered molecular dynamics calculations, coarse grained simulations, and ϕ-value analysis of the transition state.
authors.affiliation: Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, Texas 77555-0857, USA.
authors.forename: Wenzhe
authors.initials: W
authors.lastname: Lu
authors.forename: Surendra S
authors.initials: SS
authors.lastname: Negi
authors.forename: Andres F
authors.initials: AF
authors.lastname: Oberhauser
authors.forename: Werner
authors.initials: W
authors.lastname: Braun
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D002942:Circular Dichroism; D064211:Connectin; D005353:Fibronectins / Q000737:chemistry / Q000235:genetics; D006860:Hydrogen Bonding; D018625:Microscopy, Atomic Force; D056004:Molecular Dynamics Simulation; D008969:Molecular Sequence Data; D009124:Muscle Proteins / Q000737:chemistry / Q000235:genetics; D015202:Protein Engineering / Q000379:methods*; D011494:Protein Kinases / Q000737:chemistry / Q000235:genetics; D055550:Protein Stability; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry* / Q000235:genetics
chemical_list: D064211:Connectin; D005353:Fibronectins; D009124:Muscle Proteins; D011994:Recombinant Proteins; D011494:Protein Kinases