Functional role of a non-active site residue Trp23 on the enzyme activity of Escherichia coli thioesterase I/protease I/lysophospholipase L1

Angiotensin-converting enzyme 2 (ACE2) is expressed in the kidney and may be renoprotective. We determined whether urinary ACE2 enzyme activity and protein levels (ELISA), as well as angiotensinogen and ACE, are elevated during clamped euglycemia (4–6 mmol·L–1) in patients with uncomplicated type 1 diabetes (T1D, n = 58) compared with normoglycemic controls (n = 21). We also measured the effect of clamped hyperglycemia (9–11 mmol·L–1) on each urinary factor in T1D patients. Urinary ACE2 activity and protein levels were higher during clamped euglycemia in T1D compared with the controls (p < 0.0001). In contrast, urinary angiotensinogen levels (p = 0.27) and ACE excretion (p = 0.68) did not differ. In response to clamped hyperglycemia in T1D, urinary ACE2 protein decreased (p < 0.0001), whereas urinary ACE2 activity as well as angiotensinogen and ACE levels remained unchanged. Urinary ACE2 activity and protein expression are increased in T1D patients prior to the onset of clinical complications. Further work is required to determine the functional role of urinary ACE2 in early T1D.

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Role of the conserved active site residue tryptophan-24 of human dihydrofolate reductase as revealed by mutagenesis

Biochemistry ◽

10.1021/bi00219a038 ◽

1991 ◽

Vol 30 (5) ◽

pp. 1432-1440 ◽

Cited By ~ 14

Author(s):

William A. Beard ◽

James R. Appleman ◽

Shaoming Huang ◽

Tavner J. Delcamp ◽

James H. Freisheim ◽

...

Keyword(s):

Dihydrofolate Reductase ◽

Active Site ◽

Active Site Residue ◽

Human Dihydrofolate Reductase

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Role of tryptophan 248 in the active site of tryptophanase from Escherichia coli

Biochemical and Biophysical Research Communications ◽

10.1016/s0006-291x(05)80100-7 ◽

1990 ◽

Vol 173 (2) ◽

pp. 756-762 ◽

Cited By ~ 4

Author(s):

Yasushi Kawata ◽

Nobuharu Tsujimoto ◽

Shunsuke Tani ◽

Tomohiro Mizobata ◽

Masanobu Tokushige

Keyword(s):

Escherichia Coli ◽

Active Site

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Functional Role of the Conserved Active Site Proline of Triosephosphate Isomerase†,‡

Biochemistry ◽

10.1021/bi061683j ◽

2006 ◽

Vol 45 (51) ◽

pp. 15483-15494 ◽

Cited By ~ 30

Author(s):

Marco G. Casteleijn ◽

Markus Alahuhta ◽

Katrin Groebel ◽

Ibrahim El-Sayed ◽

Koen Augustyns ◽

...

Keyword(s):

Active Site ◽

Functional Role ◽

Triosephosphate Isomerase

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The role of ribonuclease II in the maturation of precursor 16S ribosomal ribonucleic acid in Escherichia coli

Biochemical Journal ◽

10.1042/bj1400443 ◽

1974 ◽

Vol 140 (3) ◽

pp. 443-450 ◽

Cited By ~ 2

Author(s):

John R. Dean ◽

John Sykes

Keyword(s):

Escherichia Coli ◽

Enzyme Activity ◽

Maximum Activity ◽

Exponential Phase ◽

Temperature Sensitive ◽

Permissive Temperature ◽

Experimental Conditions ◽

Inhibition Of Growth ◽

Ribosomal Ribonucleic Acid

The suggested involvement of ribonuclease II in the maturation of rRNA has been examined directly by determining the activity of the enzyme and the amount of p16S rRNA in cell-free extracts from Escherichia coli A19 and its temperature-sensitive derivative N464 grown under experimental conditions designed to vary the amounts of enzyme and precursor independently. In strain A19 the enzyme showed maximum activity in circumstances where the amount of p16S rRNA was normal (e.g. exponential-phase cells) or raised eight times (e.g. during inhibition of growth by methionine starvation of the relaxed auxotroph or by chloramphenicol or puromycin treatment). In strain N464 at the non-permissive temperature the ribonuclease II activity may be decreased by 50% without effect upon the amount of p16S rRNA, whereas in methionine starvation of this strain the enzyme activity is at a maximum and the p16S rRNA is eight times that in exponential-phase cells. These observations are discussed in relation to the previously implied role of ribonuclease II in the maturation of rRNA within ribosome precursors.

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The key role of a non-active-site residue Met148 on the catalytic efficiency of meta-cleavage product hydrolase BphD

Applied Microbiology and Biotechnology ◽

10.1007/s00253-013-4814-0 ◽

2013 ◽

Vol 97 (24) ◽

pp. 10399-10411 ◽

Cited By ~ 11

Author(s):

Hao Zhou ◽

Yuanyuan Qu ◽

Chunlei Kong ◽

E. Shen ◽

Jingwei Wang ◽

...

Keyword(s):

Active Site ◽

Catalytic Efficiency ◽

Cleavage Product ◽

Active Site Residue

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Analysis of the Role of the Active Site Residue Arg98 in the Flavoprotein Tryptophan 2-Monooxygenase, a Member of thel-Amino Oxidase Family†

Biochemistry ◽

10.1021/bi035299n ◽

2003 ◽

Vol 42 (47) ◽

pp. 13826-13832 ◽

Cited By ~ 19

Author(s):

Pablo Sobrado ◽

Paul F. Fitzpatrick

Keyword(s):

Active Site ◽

Active Site Residue ◽

Amino Oxidase

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HPr: a model protein

Biochemistry and Cell Biology ◽

10.1139/o95-026 ◽

1995 ◽

Vol 73 (5-6) ◽

pp. 219-222

Author(s):

J. W. Anderson

Keyword(s):

Structure Function ◽

Active Center ◽

Active Site ◽

Central Component ◽

Active Site Residue ◽

Phosphotransferase System ◽

Function Model ◽

Model Protein

Histidine-containing protein (HPr) is a central component of the bacterial phosphoenolpyruvate: sugar phosphotransferase system (PTS). This brief review covers recent structure–function studies on the active center of this protein: the role of the active center residues in phosphotransfer; the residues contributing to the phosphohydrolysis properties of HPr; and the contribution residues in HPr make to the pKaof the transiently phosphorylated active-site residue, His 15. As well, the potential for HPr to be used as a model protein for studying problems not directly associated with its function in the PTS is discussed.Key words: phosphoenolpyruvate: sugar phosphotransferase system, histidine-containing protein, active center, structure–function, model protein.

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