Osmolyte Counteracts Urea-Induced Denaturation of α-Chymotrypsin

Venkatesu, P.; Lee, Ming‐Jer; Lin, Ho-mu

doi:10.1021/jp8113013

Cited by 112 publications

(147 citation statements)

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“…Indeed, TMAO acts as a strongest stabilizer for various biomolecules. [13][14][15][16][17][18]26,60 However, in the present study TMAO proved to be a weakest stabilizer. Analogously, a similar phenomenon was observed by Bruździak et al 73 According to Bruździak et al, TMAO has acted as a weak stabilizer for hen egg white lysozyme.…”

Section: Molecular Dynamics (Md) Simulationcontrasting

confidence: 59%

“…The native structure of proteins is only marginally stable, and achieves stability/destability only within narrow ranges of conditions of co-solvent environment which can dramatically affect the protein functional activities. [8][9][10][11][12][13][14][15] It is well-known fact that even a marginal change in the natural environment around the protein may cause adverse effects on its properties. 13 The co-solvent is oen used by physical chemist or biochemist that either stabilizes or destabilizes the structures of biomolecules.…”

Section: Introductionmentioning

confidence: 99%

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Quantifying the co-solvent effects on trypsin from the digestive system of carp Catla catla by biophysical techniques and molecular dynamics simulations

et al. 2015

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Section: Molecular Dynamics (Md) Simulationcontrasting

confidence: 59%

Section: Introductionmentioning

confidence: 99%

Quantifying the co-solvent effects on trypsin from the digestive system of carp Catla catla by biophysical techniques and molecular dynamics simulations

et al. 2015

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“…Indeed, it has been shown that the stabilizing effects of methylamines and denaturing effects of urea on protein stability and function are additive (14,16,17,27,(62)(63)(64). As shown by Bolen's group, the protein backbone is the key determinant for the stabilization or denaturation by osmolytes (17,22,25).…”

Section: Discussionmentioning

confidence: 99%

“…For example, cartilaginous fish concentrate trimethylamine N-oxide (TMAO), to offset the damaging effects of urea on protein function, and it is one of the best studied protecting osmolytes (e.g. 16 -20).The mechanisms by which protecting osmolytes promote protein folding, increase protein stability, and induce conformational changes have been the focus of intense investigation (15,18,19,(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32)(33). However, nothing is known about the effects of denaturing or protecting osmolytes on the mechanical properties of PKD domains.…”

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confidence: 99%

Naturally Occurring Osmolytes Modulate the Nanomechanical Properties of Polycystic Kidney Disease Domains

Oberhauser

2010

Journal of Biological Chemistry

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Polycystin-1 (PC1) is a large membrane protein that is expressed along the renal tubule and exposed to a wide range of concentrations of urea. Urea is known as a common denaturing osmolyte that affects protein function by destabilizing their structure. However, it is known that the native conformation of proteins can be stabilized by protecting osmolytes that are found in the mammalian kidney. PC1 has an unusually long ectodomain with a multimodular structure including 16 Ig-like polycystic kidney disease (PKD) domains. Here, we used single-molecule force spectroscopy to study directly the effects of several naturally occurring osmolytes on the mechanical properties of PKD domains. This experimental approach more closely mimics the conditions found in vivo. We show that upon increasing the concentration of urea there is a remarkable decrease in the mechanical stability of human PKD domains. We found that protecting osmolytes such as sorbitol and trimethylamine N-oxide can counteract the denaturing effect of urea. Moreover, we found that the refolding rate of a structurally homologous archaeal PKD domain is significantly slowed down in urea, and this effect was counteracted by sorbitol. Our results demonstrate that naturally occurring osmolytes can have profound effects on the mechanical unfolding and refolding pathways of PKD domains. Based on these findings, we hypothesize that osmolytes such as urea or sorbitol may modulate PC1 mechanical properties and may lead to changes in the activation of the associated polycystin-2 channel or other intracellular events mediated by PC1. Polycystin-1 (PC1)2 is a large transmembrane protein, which, when mutated, cause autosomal dominant polycystic kidney disease (PKD), one of the most common lifethreatening genetic diseases, which is a leading cause of kidney failure (1). The available evidence suggests that PC1 acts as a mechanosensor, receiving signals from the primary (luminal) cilia, neighboring cells, and extracellular matrix and transduces them into cellular responses that regulate proliferation, adhesion, and differentiation that are essential for the control of renal tubules and kidney morphogenesis (1-4).PC1 is expressed along the renal tubule, where it is exposed to a wide range of concentrations of urea, from 5 mM in the proximal tubule to up to ϳ1 M in the collecting duct (5-7). Urea is known as a common denaturant that affects protein function by perturbing their structure (8). Several osmolytes have been found in the mammalian kidney that are known to counteract the effects of urea on proteins (9 -15). Among epithelial cells of the kidney medulla, the principal organic osmolytes include the polyols sorbitol and inositol, the methylamines betaine and glycerophosphocholine, and the amino acid taurine. Protecting osmolytes are found in all taxa (11,14). For example, cartilaginous fish concentrate trimethylamine N-oxide (TMAO), to offset the damaging effects of urea on protein function, and it is one of the best studied protecting osmolytes (e.g. 16 -20).The mecha...

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“…Intracellular betaine serves as an osmolyte that regulates cell volume and thereby tissue integrity (Lang 2007;Schliess and Haussinger 2002). It also serves as a "compensatory" or "counteracting" solute that stabilizes proteins and is particularly effective at countering the denaturing effect of urea (Venkatesu et al 2009). These functions of betaine have been most thoroughly studied in renal medulla, where cells are normally exposed to high extracellular osmolarity during normal operation of the urinary concentrating mechanism (Neuhofer and Beck 2005).…”

Section: Betaine and Osmoregulationmentioning

confidence: 99%

Choline and betaine in health and disease

Ueland

2010

J of Inher Metab Disea

479

388

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Choline is an essential nutrient, but is also formed by de novo synthesis. Choline and its derivatives serve as components of structural lipoproteins, blood and membrane lipids, and as a precursor of the neurotransmitter acetylcholine. Pre-and postnatal choline availability is important for neurodevelopment in rodents. Choline is oxidized to betaine that serves as an osmoregulator and is a substrate in the betaine-homocysteine methyltransferase reaction, which links choline and betaine to the folate-dependent one-carbon metabolism. Choline and betaine are important sources of one-carbon units, in particular, during folate deficiency. Choline or betaine supplementation in humans reduces concentration of total homocysteine (tHcy), and plasma betaine is a strong predictor of plasma tHcy in individuals with low plasma concentration of folate and other B vitamins (B₂, B₆, and B₁₂) in combination TT genotype of the methylenetetrahydrofolate reductase 677 C->T polymorphism. The link to one-carbon metabolism and the recent availability of food composition data have motivated studies on choline and betaine as risk factors of chronic diseases previously studied in relation to folate and homocysteine status. High intake and plasma level of choline in the mother seems to afford reduced risk of neural tube defects. Intake of choline and betaine shows no consistent relation to cancer or cardiovascular risk or risk factors, whereas an unfavorable cardiovascular risk factor profile was associated with high choline and low betaine concentrations in plasma. Thus, choline and betaine showed opposite relations with key components of metabolic syndrome, suggesting a disruption of mitochondrial choline oxidation to betaine as part of the mitochondrial dysfunction in metabolic syndrome.

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Osmolyte Counteracts Urea-Induced Denaturation of α-Chymotrypsin

Cited by 112 publications

References 64 publications

Quantifying the co-solvent effects on trypsin from the digestive system of carp Catla catla by biophysical techniques and molecular dynamics simulations

Quantifying the co-solvent effects on trypsin from the digestive system of carp Catla catla by biophysical techniques and molecular dynamics simulations

Naturally Occurring Osmolytes Modulate the Nanomechanical Properties of Polycystic Kidney Disease Domains

Choline and betaine in health and disease

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