The Role of the Side Chain on the Performance of N-type Conjugated Polymers in Aqueous Electrolytes

Four new D–A type copolymers, namely, PBDT-DFQX-PP, PBDT-DFQX-TP, PBDT-DFQX-PT and PBDT-DFQX-TT, were designed and synthesized to investigate the influence of conjugated side chain pattern on photovoltaic properties of conjugated polymers.

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Role of the phenylalanine B25 side chain in directing insulin interaction with its receptor. Steric and conformational effects.

Journal of Biological Chemistry ◽

10.1016/s0021-9258(17)38396-5 ◽

1986 ◽

Vol 261 (16) ◽

pp. 7332-7341 ◽

Cited By ~ 15

Author(s):

S H Nakagawa ◽

H S Tager

Keyword(s):

Side Chain ◽

Conformational Effects

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The role of mitochondrial cytochrome P-450 from bovine adrenal cortex in side chain cleavage of 20S,22R-dihydroxycholesterol.

Journal of Biological Chemistry ◽

10.1016/s0021-9258(19)41712-2 ◽

1975 ◽

Vol 250 (6) ◽

pp. 2283-2286

Author(s):

PF Hall ◽

JL Lewes ◽

ED Lipson

Keyword(s):

Adrenal Cortex ◽

Side Chain ◽

Mitochondrial Cytochrome ◽

Side Chain Cleavage ◽

Chain Cleavage ◽

Cytochrome P 450

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Role of Perfluorophenyl Group in the Side Chain of Small-Molecule n-Type Organic Semiconductors in Stress Stability of Single-Crystal Transistors

The Journal of Physical Chemistry Letters ◽

10.1021/acs.jpclett.0c03012 ◽

2021 ◽

pp. 2095-2101

Author(s):

Shohei Kumagai ◽

Craig P. Yu ◽

Shunsuke Nakano ◽

Tatsuro Annaka ◽

Masato Mitani ◽

...

Keyword(s):

Single Crystal ◽

Organic Semiconductors ◽

Small Molecule ◽

Side Chain

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“Newton’s cradle” proton relay with amide–imidic acid tautomerization in inverting cellulase visualized by neutron crystallography

Science Advances ◽

10.1126/sciadv.1500263 ◽

2015 ◽

Vol 1 (7) ◽

pp. e1500263 ◽

Cited By ~ 53

Author(s):

Akihiko Nakamura ◽

Takuya Ishida ◽

Katsuhiro Kusaka ◽

Taro Yamada ◽

Shinya Fushinobu ◽

...

Keyword(s):

Glycoside Hydrolases ◽

Side Chain ◽

Enzymatic Reactions ◽

X Ray Diffraction ◽

Peptide Bonds ◽

Proton Relay ◽

Newton’S Cradle ◽

Dynamics Simulations ◽

Hydrolysis Of

Hydrolysis of carbohydrates is a major bioreaction in nature, catalyzed by glycoside hydrolases (GHs). We used neutron diffraction and high-resolution x-ray diffraction analyses to investigate the hydrogen bond network in inverting cellulase PcCel45A, which is an endoglucanase belonging to subfamily C of GH family 45, isolated from the basidiomycete Phanerochaete chrysosporium. Examination of the enzyme and enzyme-ligand structures indicates a key role of multiple tautomerizations of asparagine residues and peptide bonds, which are finally connected to the other catalytic residue via typical side-chain hydrogen bonds, in forming the “Newton’s cradle”–like proton relay pathway of the catalytic cycle. Amide–imidic acid tautomerization of asparagine has not been taken into account in recent molecular dynamics simulations of not only cellulases but also general enzyme catalysis, and it may be necessary to reconsider our interpretation of many enzymatic reactions.

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The Role of Arg13 in Protein Phosphatase M tPphA from Thermosynechococcus elongatus

Enzyme Research ◽

10.1155/2012/272706 ◽

2012 ◽

Vol 2012 ◽

pp. 1-7 ◽

Cited By ~ 1

Author(s):

Jiyong Su ◽

Karl Forchhammer

Keyword(s):

Amino Acid ◽

Protein Phosphatase ◽

Arginine Residue ◽

Side Chain ◽

Wild Type ◽

Catalytic Center ◽

Nitrophenyl Phosphate ◽

Reduced Activity ◽

Amino Acid Variants

A highly conserved arginine residue is close to the catalytic center of PPM/PP2C-type protein phosphatases. Different crystal structures of PPM/PP2C homologues revealed that the guanidinium side chain of this arginine residue can adopt variable conformations and may bind ligands, suggesting an important role of this residue during catalysis. In this paper, we randomly mutated Arginine 13 of tPphA, a PPM/PP2C-type phosphatase from Thermosynechococcus elongatus, and obtained 18 different amino acid variants. The generated variants were tested towards p-nitrophenyl phosphate and various phosphopeptides. Towards p-nitrophenyl phosphate as substrate, twelve variants showed 3–7 times higher Km values than wild-type tPphA and four variants (R13D, R13F, R13L, and R13W) completely lost activity. Strikingly, these variants were still able to dephosphorylate phosphopeptides, although with strongly reduced activity. The specific inability of some Arg-13 variants to hydrolyze p-nitrophenyl phosphate highlights the importance of additional substrate interactions apart from the substrate phosphate for catalysis. The properties of the R13 variants indicate that this residue assists in substrate binding.

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