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Full-Text Articles in Food Science

Hydrophobic Probe Binding Of Β-Lactoglobulin In The Native And Molten Globule State Induced By High Pressure As Affected By Ph, Kio3 And N-Ethylmaleimide, Jian Yang, Joseph R. Powers, Stephanie Clark, A. Keith Dunker, Barry G. Swanson Aug 2002

Hydrophobic Probe Binding Of Β-Lactoglobulin In The Native And Molten Globule State Induced By High Pressure As Affected By Ph, Kio3 And N-Ethylmaleimide, Jian Yang, Joseph R. Powers, Stephanie Clark, A. Keith Dunker, Barry G. Swanson

Stephanie Clark

High hydrostatic pressure (HHP) at 500 MPa and 50 °C induces β-LG into the molten globule state. Retinol, cis-parinaric acid (CPA), and 1-anilino-naphthalene-8-sulfonate (ANS) fluorescence from pH 2.5 to 10.5 in the presence of the native and molten globule states of β-LG indicate that retinol binds to β-LG in the calyx, CPA at the surface hydrophobic site, and ANS in multiple hydrophobic sites. HHP treatment results in a decrease of β-LG affinity for retinol and CPA, suggesting conformational changes in the calyx and surface hydrophobic site of β-LG during HHP treatment. β-LG treated by HHP in the presence of N-ethylmaleimide …


Β-Lactoglobulin Molten Globule Induced By High Pressure, Jian Yang, A. Keith Dunker, Joseph R. Powers, Stephanie Clark, Barry G. Swanson Jun 2001

Β-Lactoglobulin Molten Globule Induced By High Pressure, Jian Yang, A. Keith Dunker, Joseph R. Powers, Stephanie Clark, Barry G. Swanson

Stephanie Clark

Beta-lactoglobulin (beta-LG) was treated with high hydrostatic pressure (HHP) at 600 MPa and 50 degrees C for selected times as long as 64 min. The intrinsic tryptophan fluorescence of beta-LG indicated that HHP treatment conditions induced a conformational change. HHP treatment conditions also promote a 3-fold increase in the extrinsic fluorescence of 1-anilinonaphthalene-8-sulfonate and a 2.6-fold decrease for cis-paraneric acid, suggesting an increase in accessible aromatic hydrophobicity and a decrease in aliphatic hydrophobicity. Far-ultraviolet circular dichroism (CD) spectra reveal that the secondary structure of beta-LG converts from native beta-sheets to non-native alpha-helices following HHP treatment, whereas near-ultraviolet CD spectra reveal …


High-Pressure Effects On Lysosome Integrity And Lysosomal Enzyme Activity In Bovine Muscle, Stéphanie Jung, Marie De Lamballerie-Anton, Richard G. Taylor, Mohamed Ghoul Jan 2000

High-Pressure Effects On Lysosome Integrity And Lysosomal Enzyme Activity In Bovine Muscle, Stéphanie Jung, Marie De Lamballerie-Anton, Richard G. Taylor, Mohamed Ghoul

Stéphanie Jung

This study was conducted to determine whether the application of high hydrostatic pressure could modify the enzymatic activity and membrane integrity of lysosomes in muscle. Several combinations of pressure (0-600 MPa) and time (0-300 s) were applied to two types of samples: purified enzymes (cathepsin D and acid phosphatase) in buffer solution and intact muscle (biceps femoris). The enzymes studied showed varying degrees of susceptibility depending on the level of pressure, holding time, and environment. Acid phosphatase activity was minimally affected by pressure in buffer solution, whereas cathepsin D was modulated significantly by the pressure and time applied. The activities …