Dissipative Organization of DNA Oligomers for Transient Catalytic Function

Chemo- and site-specific modifications in oligonucleotides have wide applicability as mechanistic probes in chemical biology. Here we have employed a classical reaction in organic chemistry, reductive amination, to selectively functionalize the N<sup>2</sup>-amine of guanine/2’-deoxyguanine monophosphate. This method specifically modifies guanine in several tested DNA oligonucleotides, while leaving the other bases unaffected. Using this approach, we have successfully incorporated desired handles chemoselectively into DNA oligomers.

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Faculty Opinions recommendation of Improving catalytic function by ProSAR-driven enzyme evolution.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1075795.528709 ◽

2007 ◽

Author(s):

Christopher Thanos

Keyword(s):

Enzyme Evolution ◽

Catalytic Function

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Biochemical study of fibrinolytic protease from Euphausia superba possessing multifunctional serine protease activity

Protein and Peptide Letters ◽

10.2174/0929866527666201112123714 ◽

2020 ◽

Vol 27 ◽

Author(s):

Guo-Ying Qian ◽

Gyutae Lim ◽

Shang-Jun Yin ◽

Jun-Mo Yang ◽

Jinhyuk Lee ◽

...

Keyword(s):

Defense Mechanisms ◽

Fluorescence Spectra ◽

Biochemical Study ◽

Euphausia Superba ◽

Md Simulations ◽

Time Interval ◽

Serine Residue ◽

Catalytic Function ◽

Serine Protease Activity ◽

Key Residues

Background: Background: Fibrinolytic protease from Euphausia superba (EFP) was isolated. Objective: Biochemical distinctions, regulation of the catalytic function, and the key residues of EFP were investigated. Methods: The serial inhibition kinetic evaluations coupled with measurements of fluorescence spectra in the presence of 4- (2-aminoethyl) benzene sulfonyl fluoride hydrochloride (AEBSF) was conducted. The computational molecular dynamics (MD) simulations were also applied for a comparative study. Results: The enzyme behaved as a monomeric protein with a molecular mass of about 28.6 kD with Km BApNA = 0.629 ± 0.02 mM and kcat/Km BApNA = 7.08 s-1 /mM. The real-time interval measurements revealed that the inactivation was a first-order reaction, with the kinetic processes shifting from a monophase to a biphase. Measurements of fluorescence spectra showed that serine residue modification by AEBSF directly caused conspicuous changes of the tertiary structures and exposed hydrophobic surfaces. Some osmolytes were applied to find protective roles. These results confirmed that the active region of EFP is more flexible than the overall enzyme molecule and serine, as the key residue, is associated with the regional unfolding of EFP in addition to its catalytic role. The MD simulations were supportive to the kinetics data. Conclusion: Our study indicated that EFP has an essential serine residue for its catalyst function and associated folding behaviors. Also, the functional role of osmolytes such as proline and glycine that may play a role in defense mechanisms from environmental adaptation in a krill’s body was suggested.

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Monotheism in Isaiah

The Oxford Handbook of Isaiah ◽

10.1093/oxfordhb/9780190669249.013.22 ◽

2020 ◽

pp. 218-248

Author(s):

Matthias Albani

Keyword(s):

Historical Context ◽

The Other ◽

Divine Power ◽

Crisis Situation ◽

Catalytic Function ◽

Other Hand ◽

The Future ◽

The One ◽

Religious Crisis

The monotheistic confession in Isa 40–48 is best understood against the historical context of Israel’s political and religious crisis situation in the final years of Neo-Babylonian rule. According to Deutero-Isaiah, Yhwh is unique and incomparable because he alone truly predicts the “future” (Isa 41:22–29)—currently the triumph of Cyrus—which will lead to Israel’s liberation from Babylonian captivity (Isa 45). This prediction is directed against the Babylonian deities’ claim to possess the power of destiny and the future, predominantly against Bel-Marduk, to whom both Nabonidus and his opponents appeal in their various political assertions regarding Cyrus. According to the Babylonian conviction, Bel-Marduk has the universal divine power, who, on the one hand, directs the course of the stars and thus determines the astral omens and, on the other hand, directs the course of history (cf. Cyrus Cylinder). As an antithesis, however, Deutero-Isaiah proclaims Yhwh as the sovereign divine creator and leader of the courses of the stars in heaven as well as the course of history on earth (Isa 45:12–13). Moreover, the conflict between Nabonidus and the Marduk priesthood over the question of the highest divine power (Sîn versus Marduk) may have had a kind of “catalytic” function in Deutero-Isaiah’s formulation of the monotheistic confession.

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Probing the role of lysines and arginines in the catalytic function of cytochrome P450d by site-directed mutagenesis. Interaction with NADPH-cytochrome P450 reductase

Journal of Biological Chemistry ◽

10.1016/s0021-9258(19)67801-4 ◽

1991 ◽

Vol 266 (6) ◽

pp. 3372-3375

Author(s):

T Shimizu ◽

T Tateishi ◽

M Hatano ◽

Y Fujii-Kuriyama

Keyword(s):

Cytochrome P450 ◽

Site Directed Mutagenesis ◽

Directed Mutagenesis ◽

Cytochrome P450 Reductase ◽

Nadph Cytochrome ◽

P450 Reductase ◽

Catalytic Function ◽

Nadph Cytochrome P450 Reductase

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Important Role for Phylogenetically Invariant PP2Acα Active Site and C-Terminal Residues Revealed by Mutational Analysis in Saccharomyces cerevisiae

Genetics ◽

10.1093/genetics/156.1.21 ◽

2000 ◽

Vol 156 (1) ◽

pp. 21-29 ◽

Cited By ~ 1

Author(s):

David R H Evans ◽

Brian A Hemmings

Keyword(s):

Protein Interactions ◽

Active Site ◽

Protein Function ◽

Mutational Analysis ◽

Yeast Cells ◽

Temperature Sensitive ◽

Active Site Residues ◽

Catalytic Function

Abstract PP2A is a central regulator of eukaryotic signal transduction. The human catalytic subunit PP2Acα functionally replaces the endogenous yeast enzyme, Pph22p, indicating a conservation of function in vivo. Therefore, yeast cells were employed to explore the role of invariant PP2Ac residues. The PP2Acα Y127N substitution abolished essential PP2Ac function in vivo and impaired catalysis severely in vitro, consistent with the prediction from structural studies that Tyr-127 mediates substrate binding and its side chain interacts with the key active site residues His-118 and Asp-88. The V159E substitution similarly impaired PP2Acα catalysis profoundly and may cause global disruption of the active site. Two conditional mutations in the yeast Pph22p protein, F232S and P240H, were found to cause temperature-sensitive impairment of PP2Ac catalytic function in vitro. Thus, the mitotic and cell lysis defects conferred by these mutations result from a loss of PP2Ac enzyme activity. Substitution of the PP2Acα C-terminal Tyr-307 residue by phenylalanine impaired protein function, whereas the Y307D and T304D substitutions abolished essential function in vivo. Nevertheless, Y307D did not reduce PP2Acα catalytic activity significantly in vitro, consistent with an important role for the C terminus in mediating essential protein-protein interactions. Our results identify key residues important for PP2Ac function and characterize new reagents for the study of PP2A in vivo.

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