Spectrofluorimetric assessment of the surface hydrophobicity of proteins

Cardamone, Michael; Puri, N K

doi:10.1042/bj2820589

Cited by 463 publications

(328 citation statements)

References 18 publications

Supporting

Mentioning

314

Contrasting

Unclassified

Order By: Relevance

“…Acrolein-modified apoE3-NT elicited a similar λ max , but with a 50% decrease in fluorescence emission intensity. In a complementary approach, we employed ANS, an extrinsic fluorophore that interacts with "hydrophobic patches" on the protein to assess possible acrolein-modification induced changes in the tertiary fold, Figure 5, Panel B. ANS is routinely employed to evaluate surface hydrophobicity on proteins (28,29,35), which is directly correlated with the fluorescence intensity. In the absence of protein, an aqueous solution of ANS in TBS elicits a very low fluorescence with a spectrum centered ∼520 nm.…”

Section: Resultsmentioning

confidence: 99%

Modification by Acrolein, a Component of Tobacco Smoke and Age-Related Oxidative Stress, Mediates Functional Impairment of Human Apolipoprotein E

et al. 2007

View full text Add to dashboard Cite

Oxidative damage to proteins such as apolipoprotein B100 increases the atherogenicity of low density lipoproteins (LDL). However, little is known about the potential oxidative damage to apolipoprotein E (apoE), an exchangeable anti-atherogenic apolipoprotein. ApoE plays an integral role in lipoprotein metabolism by regulating the plasma cholesterol and triglyceride levels. Hepatic uptake of lipoproteins is facilitated by apoE's ability to bind with cell surface heparan sulfate proteoglycans and to lipoprotein receptors via basic residues in its 22 kDa N-terminal domain (NT). We investigated the effect of acrolein, an aldehydic product of endogenous lipid peroxidation and a tobacco smoke component, on the conformation and function of recombinant human apoE3-NT. Acrolein caused oxidative modification of apoE3-NT as detected by Western blot with acrolein-lysine-specific antibodies, and tertiary conformational alterations. Acrolein-modification impairs the ability of apoE3-NT to interact with heparin and the LDL receptor. Furthermore, acrolein-modified apoE3-NT displayed a 5-fold decrease in its ability to interact with lipid surfaces. Our data indicate that acrolein disrupts the functional integrity of apoE3, which likely interferes with its role in regulating plasma cholesterol homeostasis. These observations have implications regarding the role of apoE in the pathogenesis of smoking-and oxidative stress-mediated cardiovascular and cerebrovascular diseases. KeywordsCardiovascular disease; apolipoprotein E; acrolein; tobacco smoke; oxidative stress; aging; LDL receptor; heparan sulfate proteoglycan; lysine modification Oxidative stress is recognized as a major factor in the onset of atherosclerosis, cardiovascular disease and stroke in humans; of several factors that lead to increased oxidative stress, aging and life style (diet, smoking) play crucial roles. Atherosclerosis is characterized by the intracellular and extra cellular deposition of low density lipoproteins (LDL) in macrophages (1). Oxidative modification of plasma LDL leads to their uptake by scavenger receptors located The role of apoE in cholesterol metabolism emerged from studies with transgenic mice over expressing apoE, which manifested decreased plasma cholesterol levels on a chow diet and a marked resistance to hypercholesterolemia when fed a cholesterol rich diet (4). On the other hand, apoE-deficient subjects develop symptoms of type III hyperlipoproteinemia (5), with elevated plasma cholesterol levels and accumulation of particles bearing size in the very low density lipoprotein (VLDL) and intermediate density lipoprotein (IDL) range (6,7). Further, inactivation of apoE by gene targeting leads to accumulation of cholesterol-rich remnant lipoproteins and spontaneous atherosclerotic lesions in mice (8,9). Taken together, these early studies have established the key role of apoE in regulating plasma cholesterol and triglyceride levels, which are recognized as indicators of heart disease. The focus of this study is to investigate the role ...

show abstract

Section: Resultsmentioning

confidence: 99%

Modification by Acrolein, a Component of Tobacco Smoke and Age-Related Oxidative Stress, Mediates Functional Impairment of Human Apolipoprotein E

et al. 2007

View full text Add to dashboard Cite

show abstract

“…Further study on the determination of number of ANS-binding site (n) was performed according to the report described by Cardamon and Puri [11]. For MalZ, the n value was calculated to be 0.24.…”

Section: Discussionmentioning

confidence: 99%

“…6) the surface hydrophobicity of MalZ was calculated to be 150.7. The solubility and aggregation properties of a protein under physiological conditions are typically determined by the number and relative sizes of the surface hydrophobic sites [11,16]. Earlier experimental results reported the surface hydrophobicity value of few proteins like BTSI, lysozyme, ovalbumin, and β-lactoglobulin [10] and among them BTSI has the lowest surface hydrophobicity value of 1.14, lysozyme and ovalbumin have the values of 2.26 and 12, respectively, and β-lactoglobulin has the highest surface hydrophobicity value of 468.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Unfolding Studies of Escherichia coli Maltodextrin Glucosidase Monitored by Fluorescence Spectroscopy

et al. 2008

View full text Add to dashboard Cite

Equilibrium unfolding of a 69-kDa monomeric Escherichia coli maltodextrin glucosidase (MalZ) was studied using intrinsic and extrinsic fluorescence spectroscopy. The unfolding transition of MalZ followed a three-state process, involving the formation of a stable intermediate state having more exposed hydrophobic surface. It was found that the protein structure can be easily perturbed by low concentration of guanidium hydrochloride (GdnHCl) and, at a GdnHCl concentration of 2 M, MalZ was denatured completely. The active site of the protein also has been proved to be sensitive to a low concentration of GdnHCl since MalZ deactivated at 0.5 M GdnHCl completely. The surface hydrophobicity and ANS-binding site of the protein have been determined to be 150.7 and 0.24, respectively. Perhaps the formation of the stable unfolding intermediate, having higher surface hydrophobicity, may be one of the reasons for aggregation of MalZ and its recognition by chaperonin GroEL during the assisted folding pathway.

show abstract

“…Hydrophobic regions regulate interactions between proteins based on the number and size of hydrophobic sites on the protein surface. This determines the solubility and susceptibility to aggregation under the physiological conditions of pH, temperature, and ionic strength (Cardamone & Puri, 1992).…”

Section: The Effect Of Ionic Strength On Gelationmentioning

confidence: 99%

Thermal gelation of myofibrillar proteins from aquatic organisms

Tolano-Villaverde

Torres‐Arreola

Ocaño‐Higuera

et al. 2015

CyTA - Journal of Food

View full text Add to dashboard Cite

Gelling ability is attributed to myosin, which is the main myofibrillar protein. Therefore, its integrity is very important. However, a gel with good textural characteristics and stability depends on the inherent characteristics of its proteins, as well as on external factors (primarily temperature, pH, protein concentration and added salt). The best gels from aquatic organism proteins are obtained at a pH value of approximately 7.0. However, the concentration of salt is often variable. In contrast, when proteins are recovered using acid/alkaline dissolution, gels with good textural characteristics are obtained without salt. Hydrophobic interactions, disulfide bonds, hydrogen bonds, and electrostatic interactions are the main interactions that stabilize the protein gel. Thus, this review focuses on the study of the main factors involved in protein gelation, as well as on the extraction method effect on the gelling capacity of proteins from aquatic organisms. Gelificación térmica de proteínas miofibrilares de organismos acuáticos RÉSUMÉMiosina es la principal proteína miofibrilar a la cual se le atribuye la habilidad gelificante, por lo tanto su integridad es muy importante. Sin embargo, las propiedades texturales y estabilidad de los geles depende de las características inherentes de sus proteínas, así como de factores externos (principalmente temperatura, pH, concentración de proteína y sal añadida). En general, los mejores geles proteicos obtenidos de organismos acuáticos se obtienen a pH cercano a 7.0, mientras que la concentración de sal suele ser variable; sin embargo, cuando la recuperación de proteínas se realiza a través de disoluciones ácidas/alcalinas, es posible obtenerse geles con buenas características texturales en ausencia de sal. Las principales interacciones involucradas en la estabilización de geles proteicos son: interacciones hidrofóbicas, puentes disulfuro, puentes de indrógeno e interacciones electrostáticas. Por esta razón, la presente revisión estudia los principales factores involucrados en la gelificación proteica, así como el efecto del método de extracción, sobre la capacidad gelificante de proteínas de organismos acuáticos. ARTICLE HISTORY

show abstract

Spectrofluorimetric assessment of the surface hydrophobicity of proteins

Cited by 463 publications

References 18 publications

Modification by Acrolein, a Component of Tobacco Smoke and Age-Related Oxidative Stress, Mediates Functional Impairment of Human Apolipoprotein E

Modification by Acrolein, a Component of Tobacco Smoke and Age-Related Oxidative Stress, Mediates Functional Impairment of Human Apolipoprotein E

Unfolding Studies of Escherichia coli Maltodextrin Glucosidase Monitored by Fluorescence Spectroscopy

Thermal gelation of myofibrillar proteins from aquatic organisms

Contact Info

Product

Resources

About