Jin Kim Montclare Polytechnic Institute of NYU Department of Chemical and Biological Sciences March 22, 2010 Engineered Protein Biomaterials

Protein Interactions: Intra- and Extracellular Matrix Functional role Structural role

In vivo incorporation of unnatural amino acids

Amino acid analogs incorporated into E. coli proteins

Wagner G. et al. Nature 1999, 400, 86; Poux, A. N. and Marmorstein R. Biochemistry 2003, 42, 14366; Treivel, R.C., Li, F.-Y. and Marmorstein, R. Anal. Biochem. 2000, 287, 319. Histone acetyltransferase tGcn5 C-terminus specificity N-terminus affinity 10 Phe’s distributed Question: How does fluorinated phenylalanines influence stability, function and selectivity of tGcn5?

Histone acetylation or Transcription factor acetylation--> birth defects, cancers, heart disorders Histone Acetyltransferases (HATs) Transcription factor p53 Histone

Variants with altered substrate specificity K. Mehta Two variants pFF-F112R and pFF-112R-Q114L exhibit a preference for p53 with no measurable activity for target histone H3. H3 p53 K cat /k m (mM -1 s -1 )

Selectivity switch by integrating chemical and genetic diversity Combination of unnatural amino acid incorporation with mutagenesis modulates substrate specificity. Transcription factor p53 Histone pFF- F112R pFF- F112R pFF- F112R X

Protein Interactions: Intra- and Extracellular Matrix Functional role Structural role

Mono-dispersity Proteins (PLGAs) Synthetic Polymer (PMMA) I. Chen and B. Gao Anal. Chem., 1997, 69, 4399 Well defined secondary structures [(AG) x EG] n Krejchi et.al. Science, 1994, 265, 1427 Chain length, sequence and stereochemistry Biopolymer Synthesis

Block polymers of 2 different self-assembling domains (SADs) Understand self-assembly, control hierarchical organization Integrate signaling molecules Control binding of small molecules: delivery Tunable smart materials Control temperature- dependent assembly Orientation of SADs influence Structure and assembly

Vitamin D3 Cartilage oligomeric matrix protein coiled coil (COMPcc) Ozbeck, S., Engel, J., Stetefeld, J. EMBO J. 2002, 21, Comprised of homopentamer of coiled coils Hydrophobic pore 7.3 nm long and nm diameter Binds the hormone 1,25-dihydroxy (vitamin D3)

Comprised of pentapeptide repeat (GVPXP) n Exhibits lower critical solution temperature (LCST) depends on identity of X and number of repeats Urry, D.W. and Parker, T.M. J. Muscle Res Cell Mot. 2002, 23, 543. Elastin polypeptide

Secondary structure and stability characterization The orientation of fusion does make a difference on overall structure of di- blocks The number of blocks play an important role in overall conformation and temperature dependent behavior of block polymers Influence of vit D on the polymer structure and assembly is dependent on block orientation and composition J. Haghpanah, C. Yuvienco EC CECE ECE 6.9 o C o C 1.3 o C

TEM Analysis of Block Polymers: Particle-Fiber Switch EC and ECE look to have similar features with slightly larger sizes when compared to CE, consistent with DLS While ECE is larger in molecular weight, the article sizes are slightly smaller than EC. J. Haghpanah, E. Roth EC CECE ECE nm nm nm

Block Polymer Binding of ATR and Ccm via Fluorescence J. Haghpanah, H. Barra CE: binds best to ATR and Ccm indicating importance of N-terminal C domain ECE and EC: additional C-terminal E domain improves binding

Microrheology of Block Polymers J. Haghpanah, R. Tu 9.6 mg/ mL 4.8 mg/ mL ECCECE ECE EC: elastic, CE: viscous and ECE: viscoelastic--orientation and block number important

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