pH Dependence of Formation of a Partially Unfolded State of a Lys 73 → His Variant of Iso-1-cytochromec:  Implications for the Alkaline Conformational Transition of Cytochromec†

Biochemistry ◽  
2000 ◽  
Vol 39 (44) ◽  
pp. 13584-13594 ◽  
Author(s):  
Carma J. Nelson ◽  
Bruce E. Bowler
Keyword(s):  
Conformational Transition ◽  
Ph Dependence ◽  
Unfolded State ◽  
Alkaline Conformational Transition ◽  
Partially Unfolded

Improved Stability of a Protein Vaccine Through Elimination of a Partially Unfolded State

2004 ◽  
Author(s):  
Colleen A. McHugh ◽  
Ralph F. Tammariello ◽  
Charles B. Millard ◽  
John H. Carra
Keyword(s):  
Protein Vaccine ◽  
Unfolded State ◽  
Improved Stability ◽  
Partially Unfolded

Cold Shock Domain of the Human Y-Box Protein YB-1. Backbone Dynamics and Equilibrium between the Native State and a Partially Unfolded State†

Biochemistry ◽  
2004 ◽  
Vol 43 (31) ◽  
pp. 10237-10246 ◽  
Author(s):  
Cathelijne P. A. M. Kloks ◽  
Marco Tessari ◽  
Geerten W. Vuister ◽  
Cornelis W. Hilbers
Keyword(s):  
Cold Shock ◽  
Backbone Dynamics ◽  
Native State ◽  
Unfolded State ◽  
Cold Shock Domain ◽  
Partially Unfolded

Equilibrium Studies of the Reaction of Turkey (Meleagris gallopavo) Haemoglobin Sulphydryl Groups with 5,5′-dithiobis(2-nitrobenzoate): Tertiary Conformational Change in Turkey Haemoglobin Induced by Inositol hexakisphosphate

2014 ◽  
Vol 4 (4) ◽  
pp. 200-206
Author(s):  
C. O. Ehi-Eromosele ◽  
A. Edobor-Osoh ◽  
C. O. Ajanaku ◽  
W. U. Anake ◽  
O. Aladesuyi ◽  
...  
Keyword(s):  
Conformational Transition ◽  
Ph Dependence ◽  
Meleagris Gallopavo ◽  
Relative Distribution ◽  
Minor Components ◽  
Protein Conformations ◽  
Inositol Hexakisphosphate ◽  
Equilibrium Studies ◽  
Relative Population ◽  
Sulphydryl Groups

The red blood cell of turkey contains two haemoglobin types, major and minor components. In the present study, the equilibrium constant, Kequ, for the reaction of 5,5′-dithiobis(2-nitrobenzoate), DTNB, with the sulphydryl group of the major turkey aquomethaemoglobin was determined at 25°C as a function of pH. Kequ varies by about 2 to 3 orders of magnitude between pH 5.6 and 9.0 for both haemoglobin [stripped and in the presence of inositol hexakisphosphate (inositol-P6)]. Calculations from the pH dependence of Kequ showed that in the r ⇌ t tertiary conformational transition of aquomethae-moglobin, the t isomer population was 0.26 %. In the presence of inositol-P6, the t isomer population increased to 9.08 %. The results showed that while inositol-P6 increased the relative population of the t tertiary conformation by changing the relative distribution of two protein conformations, it had no effect on Kequ. The effect of Inositol-P6 on the nature and number of groups linked to the DTNB reaction was also determined.

A pH-dependent conformational transition of Aβ peptide and physicochemical properties of the conformers in the glial cell

2002 ◽  
Vol 361 (3) ◽  
pp. 547-556 ◽  
Author(s):  
Yoichi MATSUNAGA ◽  
Nobuhiro SAITO ◽  
Akihiro FUJII ◽  
Junichi YOKOTANI ◽  
Tadakazu TAKAKURA ◽  
...  
Keyword(s):  
Glial Cell ◽  
Conformational Changes ◽  
Conformational Transition ◽  
Early Stage ◽  
Ph Dependence ◽  
Amyloid Β ◽  
Proteinase K ◽  
Aβ Peptide ◽  
Ph Dependent ◽  
Insight Into

In the present study we identified the epitopes of antibodies against amyloid β-(1–42)-peptide (Aβ1–42): 4G8 reacted with peptides corresponding to residues 17–21, 6F/3D reacted with peptides corresponding to residues 9–14, and anti 5-10 reacted with peptides corresponding to residues 5–10. The study also yielded some insight into the Aβ1–42 structures resulting from differences in pH. An ELISA study using monoclonal antibodies showed that pH-dependent conformational changes occur in the 6F/3D and 4G8 epitopes modified at pH 4.6, but not in the sequences recognized by anti 1-7 and anti 5-10. This was unique to Aβ1–40 and Aβ1–42 and did not occur with Aβ1–16 or Aβ17–42. The reactivity profile of 4G8 was not affected by blockage of histidine residues of pH-modified Aβ1–40 and Aβ1–42 with diethyl pyrocarbonate; however, the mutant [Gln11]Aβ1–40 abrogated the unique pH-dependence towards 4G8 observed with Aβ1–40. These findings suggest that these epitopes are cryptic at pH4.6, and that Glu11 is responsible for the changes. We suggest that the abnormal folding of 6F/3D epitope affected by pH masked the 4G8 epitope. A study of the binding of metal ions to Aβ1–42 suggested that Cu2+ and Zn2+ induced a conformational transition around the 6F/3D region at pH7.4, but did not affect the region when it was modified at pH4.6. However, Fe2+ had no effect, irrespective of pH. Aβ modified at pH 4.6 appeared to be relatively resistant to proteinase K compared with Aβs modified at pH7.4, and the former might be preferentially internalized and accumulated in a human glial cell. Our findings suggest the importance of microenvironmental changes, such as pH, in the early stage of formation of Aβ aggregates in the glial cell.

scholarly journals A superior drug carrier – aponeocarzinostatin in partially unfolded state fully protects the labile antitumor enediyne

2009 ◽  
Vol 16 (1) ◽  
pp. 48 ◽  
Author(s):  
Aranganathan Shanmuganathan ◽  
Thallapuranam Kumar ◽  
Chiy-Mey Huang ◽  
Chin Yu ◽  
Der-Hang Chin
Keyword(s):  
Drug Carrier ◽  
Unfolded State ◽  
Partially Unfolded

Bacterial Expression of a Mitochondrial Cytochromec. Trimethylation of Lys72 in Yeastiso-1-Cytochromecand the Alkaline Conformational Transition†

Biochemistry ◽  
1998 ◽  
Vol 37 (17) ◽  
pp. 6124-6131 ◽  
Author(s):  
W. Brent R. Pollock ◽  
Federico I. Rosell ◽  
Mark B. Twitchett ◽  
Mark E. Dumont ◽  
A. Grant Mauk
Keyword(s):  
Conformational Transition ◽  
Bacterial Expression ◽  
Alkaline Conformational Transition

Salt as a catalyst in the mitochondria: returning cytochrome c to its native state after it misfolds on the surface of cardiolipin containing membranes

2014 ◽  
Vol 50 (28) ◽  
pp. 3674-3676 ◽  
Author(s):  
Leah A. Pandiscia ◽  
Reinhard Schweitzer-Stenner
Keyword(s):  
Cytochrome C ◽  
Native State ◽  
Unfolded State ◽  
Partially Unfolded

After binding to TOCL/DOPC(20%/80%) liposomes ferricytochrome c remains mostly in its partially unfolded state under folding conditions. The addition of 100 mM NaCl switches it back to the native state.

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