A β-sheet structure interacting peptide for intracellular protein delivery into human pluripotent stem cells and their derivatives.

The advance in stem cell research relies largely on the efficiency and biocompatibility of technologies used to manipulate stem cells. In our previous study, we had designed an amphipathic peptide RV24 that can deliver proteins into cancer cell lines efficiently without significant side effects. Encouraged by this observation, we moved forward to test whether RV24 could be used to deliver proteins into human embryonic stem cells and human induced pluripotent stem cells.

Structural, stability, dynamic and binding properties of the ALS-causing T46I mutant of the hVAPB MSP domain as revealed by NMR and MD simulations.

T46I is the second mutation on the hVAPB MSP domain which was recently identified from non-Brazilian kindred to cause a familial amyotrophic lateral sclerosis (ALS). Here using CD, NMR and molecular dynamics (MD) simulations, we characterized the structure, stability, dynamics and binding capacity of the T46I-MSP domain. The results reveal: 1) unlike P56S which we previously showed to completely eliminate the native MSP structure, T46I leads to no significant disruption of the native secondary and tertiary structures, as evidenced from its far-UV CD spectrum, as well as Cα and Cβ NMR chemical shifts.

Dynamically-driven inactivation of the catalytic machinery of the SARS 3C-like protease by the N214A mutation on the extra domain.

Despite utilizing the same chymotrypsin fold to host the catalytic machinery, coronavirus 3C-like proteases (3CLpro) noticeably differ from picornavirus 3C proteases in acquiring an extra helical domain in evolution. Previously, the extra domain was demonstrated to regulate the catalysis of the SARS-CoV 3CLpro by controlling its dimerization. Here, we studied N214A, another mutant with only a doubled dissociation constant but significantly abolished activity.

Elimination of the native structure and solubility of the hVAPB MSP domain by the Pro56Ser mutation that causes amyotrophic lateral sclerosis.

The Pro56Ser mutation in the human VAPB MSP domain causes a familial amyotrophic lateral sclerosis. Here we present the first structural investigation of both wild-type and Pro56Ser mutant MSP domains. The results reveal that the wild-type MSP domain is well-folded at neutral pH but can undergo acid-induced unfolding reversibly.

Identification, recombinant production and structural characterization of four silk proteins from the Asiatic honeybee Apis cerana.

Unlike silkworm and spider silks assembled from very large and repetitive fibrous proteins, the bee and ant silks were recently demonstrated to consist of four small and non-repetitive coiled-coil proteins. The design principle for this silk family remains largely unknown and so far no structural study is available on them in solution. The present study aimed to identify, express and characterize the Asiatic honeybee silk proteins using DLS, CD and NMR spectroscopy.