This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Although a large number of enzymes use zinc to perform hydrolytic reactions there are deficiencies in the understanding of the factors that rule their hydrolytic activity and an overall shortage of structure/reactivity correlations. Attempts at engineering catalytic zinc sites have failed in reproducing the catalytic efficiencies seen in native enzymes . Recent PDB surveys show that the second shell (the environment surrounding the metal and its respective ligands) is not hydrophobic, as had once been believed, but rather is more polar than nonpolar (1,2). If our goal is to understand how the environment of enzyme active sites controls the reactivity of the metals then we must begin to look beyond the first shell representation so often used to describe metal active sites and investigate how networks of interactions work together to control and fine-tune chemistry. To understand the role of various conserved second and first shell residues we have constructed and crystallized a number of mutations of the bridged bimetalloprotease of Aeromonas proteolytica (AAP). AAP is asmall aminopeptidase that efficiently catalyzes the hydrolysis of bulky hydrophobic amino acids from the N-terminus of peptides. The mechanism of AAP has been pieced together by kinetic, spectroscopic, and crystallographic studies (Holz review). The role of the dizinc center is to activate the attacking water, stabilize transition state charge, and help orientthe substrate. A 1.2 Angstrom data of a particular second shell mutant, S228A, shows that theaspartate that is directly coordinated to Zn2 exhibits monodentate-like rather than equivalentbidentate binding seen with wild type. The pH kinetic experiments produce an inflection of kcat at around pH 7.8 where the wild type enzyme has none. It is possible that the change in the position of the aspartate allows for its protonation which may in turn attenuate the anionic carboxylate ligand, causing an increase in Lewis acidity at the metals.
| Weingarten, Adam S; Dannenhoffer, Adam J; Kazantsev, Roman V et al. (2018) Chromophore Dipole Directs Morphology and Photocatalytic Hydrogen Generation. J Am Chem Soc 140:4965-4968 |
| Yang, Cheolhee; Choi, Minseo; Kim, Jong Goo et al. (2018) Protein Structural Dynamics of Wild-Type and Mutant Homodimeric Hemoglobin Studied by Time-Resolved X-Ray Solution Scattering. Int J Mol Sci 19: |
| Kazantsev, Roman V; Dannenhoffer, Adam J; Weingarten, Adam S et al. (2017) Crystal-Phase Transitions and Photocatalysis in Supramolecular Scaffolds. J Am Chem Soc 139:6120-6127 |
| Fournier, Bertrand; Sokolow, Jesse; Coppens, Philip (2016) Analysis of multicrystal pump-probe data sets. II. Scaling of ratio data sets. Acta Crystallogr A Found Adv 72:250-60 |
| Cho, Hyun Sun; Schotte, Friedrich; Dashdorj, Naranbaatar et al. (2016) Picosecond Photobiology: Watching a Signaling Protein Function in Real Time via Time-Resolved Small- and Wide-Angle X-ray Scattering. J Am Chem Soc 138:8815-23 |
| Pande, Kanupriya; Hutchison, Christopher D M; Groenhof, Gerrit et al. (2016) Femtosecond structural dynamics drives the trans/cis isomerization in photoactive yellow protein. Science 352:725-9 |
| Weingarten, Adam S; Kazantsev, Roman V; Palmer, Liam C et al. (2015) Supramolecular Packing Controls H? Photocatalysis in Chromophore Amphiphile Hydrogels. J Am Chem Soc 137:15241-6 |
| Pfoh, Roland; Pai, Emil F; Saridakis, Vivian (2015) Nicotinamide mononucleotide adenylyltransferase displays alternate binding modes for nicotinamide nucleotides. Acta Crystallogr D Biol Crystallogr 71:2032-9 |
| Mariette, Céline; Guérin, Laurent; Rabiller, Philippe et al. (2015) The creation of modulated monoclinic aperiodic composites in n-alkane/urea compounds. Z Kristallogr Cryst Mater 230:5-11 |
| Yang, Xiaojing; Stojkovi?, Emina A; Ozarowski, Wesley B et al. (2015) Light Signaling Mechanism of Two Tandem Bacteriophytochromes. Structure 23:1179-89 |
Showing the most recent 10 out of 120 publications
