Structural studies of a Phe256Trp mutant of human salivary α-amylase: implications for the role of a conserved water molecule in enzyme activity

Ramasubbu, Narayanan; Sundar, Krishnan; Ragunath, Chandran; Rafi, Mohamed

doi:10.1016/j.abb.2003.10.007

Cited by 22 publications

(14 citation statements)

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“…Structural studies have shown that water chains exist in gramicidin A membrane channels, [7] bacteriorhodopsin, [8] and α-amylase [9] for rapid transport of protons and act as "proton wires". The observation of water chains in porous materials [10] and organic hosts [11] exhibiting supramolecular interactions has significantly advanced the understanding of the structures and functions of water chains in biological systems.…”

Section: Introductionmentioning

confidence: 99%

Tapes of Cyclic Water Tetramers in the Double‐Helical Complex[Cd₂(bpa)₂Cl₄]·6 H₂O

Sun

et al. 2005

Eur J Inorg Chem

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Section: Introductionmentioning

confidence: 99%

Tapes of Cyclic Water Tetramers in the Double‐Helical Complex[Cd₂(bpa)₂Cl₄]·6 H₂O

Sun

et al. 2005

Eur J Inorg Chem

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“…Therefore, controlling its level, via inhibiting the activities of α-glucosidase enzymes, is believed to be an important strategy to manage this disease. Alfaglucosidase enzyme is a member of the glucosidases located in the brush-border surface membrane of the intestinal cells and is a rate-limiting step in the conversion of oligosaccharides and disaccharides into monosaccharides, necessary for gastrointestinal absorption [13] . In addition, α-amylase, which is present in both salivary and pancreatic secretions [14] , is responsible for cleaving large malto-oligosaccharides to maltose which is a substrate for the intestinal α-glucosidase.…”

Section: Inhibition Of Glucose Absorptionmentioning

confidence: 99%

Phytotherapy in diabetes: Review on potential mechanistic perspectives

El‐Abhar

Schaalan

2014

WJD

108

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Diabetes mellitus (DM) is a widely spread epidemic disease that results from the absence of insulin, decreased secretion and/or impaired function. Since DM is a multifactorial disease, the available pharmaceuticals, despite their sensible treatment, target mostly one pathway to control hyperglycemia and encounter several side effects. Therefore, new therapeutic paradigms aim to hit several pathways using only one agent. Traditionally, antidiabetic plants and/or their active constituents may fulfill this need. More than 200 species of plants possess antidiabetic properties which were evaluated mostly by screening tests without digging far for the exact mode of action. Searching among the different literature resources and various database and in view of the above aspects, the present article provides a comprehensive review on the available antidiabetic plants that have been approved by pharmacological and clinical evaluations, and which their mechanism(s) of action is assured. These plants are categorized according to their proved mode of action and are classified into those that act by inhibiting glucose absorption from intestine, increasing insulin secretion from the pancreas, inhibiting glucose production from hepatocytes, or enhancing glucose uptake by adipose and muscle tissues. The current review also highlights those that mimic in their action the new peptide analogs, such as exenatide, liraglutide and dipeptidylpeptidase-4 inhibitors that increase glucagon-like peptide-1 serum concentration and slow down the gastric emptying.© 2014 Baishideng Publishing Group Co., Limited. All rights reserved.Key words: Hypoglycaemic nutraceuticals; Antidiabetic phyto-constituents; Medicinal plants; Phytotherapy; Diabetes mellitus Core tip: Diabetes is a serious metabolic disorder that is currently treated by different types of synthetic oral hypoglycemic agents, in addition to insulin. However, due to the unwanted side effects, the efficacies of these compounds are debatable and there is a demand for new compounds for the treatment of diabetes. Therefore, attention has been directed towards nutraceuticals originating from plants that are rich in antidiabetic phyto-constituents. Although the evidenced-based therapeutic usage of many plants is scarce, the plants cited in this review are those reputed traditionally for their antidiabetic effect and that were verified either experimentally or clinically.El-Abhar HS, Schaalan MF. Phytotherapy in diabetes: Review on potential mechanistic perspectives. World J Diabetes 2014; 5(2): 176-197 Available from:

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“…Among water clusters, 1-D water morphologies draw considerable interest because of their important roles in biological processes. Structural studies have shown that 1-D water morphologies exist in gramicidin A membrane channels [36], bacteriorhodopsin [37], and a-amylase [38] for rapid transport of protons and act as ''proton wires''. Very recently, significant progress has been made with respect to structural characterization of 1-D aggregates.…”

Section: Supramolecular Architecture Built Of Co(ii) and A Tripodal Lmentioning

confidence: 99%

Supramolecular architecture built of Co(II) and a tripodal ligand containing 1-D water tapes with (H₂O)₁₆ cluster units

Huang

et al. 2011

Journal of Coordination Chemistry

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The reaction of Co(NO 3 ) 2 Á 6H 2 O with a tripodal ligand leads to a new complex {[Co(L)] Á 2NO 3 Á 8H 2 O} (1) confirmed by single-crystal X-ray diffraction, infrared spectroscopy, and elemental analysis. The particular interest of 1 is in the formation of a 1-D water tape consisting of (H 2 O) 16 cluster units, the neighboring water tapes are connected by free nitrate anions via hydrogen bonds into a 2-D guest layer. These guest layers are alternately packed face-to-face with the 2-D host layers along the a-axis to form a 3-D supramolecular architecture. There exist C-H Á Á Á N and C-H Á Á Á O weak hydrogen bonds between the guest layer and host layer. These weak hydrogen bonds and water-nitrate, water-water hydrogen bonds are important for the stability of the overall structure.

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Structural studies of a Phe256Trp mutant of human salivary α-amylase: implications for the role of a conserved water molecule in enzyme activity

Cited by 22 publications

References 50 publications

Tapes of Cyclic Water Tetramers in the Double‐Helical Complex[Cd₂(bpa)₂Cl₄]·6 H₂O

Tapes of Cyclic Water Tetramers in the Double‐Helical Complex[Cd₂(bpa)₂Cl₄]·6 H₂O

Phytotherapy in diabetes: Review on potential mechanistic perspectives

Supramolecular architecture built of Co(II) and a tripodal ligand containing 1-D water tapes with (H₂O)₁₆ cluster units

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Structural studies of a Phe256Trp mutant of human salivary α-amylase: implications for the role of a conserved water molecule in enzyme activity

Cited by 22 publications

References 50 publications

Tapes of Cyclic Water Tetramers in the Double‐Helical Complex[Cd2(bpa)2Cl4]·6 H2O

Tapes of Cyclic Water Tetramers in the Double‐Helical Complex[Cd2(bpa)2Cl4]·6 H2O

Phytotherapy in diabetes: Review on potential mechanistic perspectives

Supramolecular architecture built of Co(II) and a tripodal ligand containing 1-D water tapes with (H2O)16 cluster units

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Product

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Tapes of Cyclic Water Tetramers in the Double‐Helical Complex[Cd₂(bpa)₂Cl₄]·6 H₂O

Tapes of Cyclic Water Tetramers in the Double‐Helical Complex[Cd₂(bpa)₂Cl₄]·6 H₂O

Supramolecular architecture built of Co(II) and a tripodal ligand containing 1-D water tapes with (H₂O)₁₆ cluster units