scholarly journals Free energy changes in denaturation of ribonuclease A by mixed denaturants. Effects of combinations of guanidine hydrochloride and one of the denaturants lithium bromide, lithium chloride, and sodium bromide.

1984 ◽  
Vol 259 (7) ◽  
pp. 4183-4186
Author(s):  
F Ahmad
Keyword(s):  
Free Energy ◽  
Lithium Chloride ◽  
Guanidine Hydrochloride ◽  
Lithium Bromide ◽  
Ribonuclease A ◽  
Sodium Bromide

scholarly journals THE CONVERSION OF FIBRINOGEN TO FIBRIN

1953 ◽  
Vol 36 (6) ◽  
pp. 759-766 ◽  
Author(s):  
Sidney Shulman ◽  
Sidney Katz ◽  
John D. Ferry
Keyword(s):  
Lithium Chloride ◽  
Sodium Iodide ◽  
Guanidine Hydrochloride ◽  
Lithium Bromide ◽  
Sharp Peak ◽  
Sodium Bromide ◽  
Sedimentation Constant ◽  
Fibrin Clots

1. Fibrin clots prepared in the absence of calcium can be dissolved in solutions of lithium chloride and bromide and sodium bromide and iodide, as well as of guanidine hydrochloride and urea. These salts do not denature fibrinogen under the same conditions of concentration, temperature, and time. Sedimentation experiments on the fibrin solutions show in each case a single sharp peak with a sedimentation constant close to that of fibrinogen. 2. At lower concentrations, these salts inhibit the clotting of fibrinogen by thrombin, but in the case of lithium bromide and sodium iodide, at least, allow an intermediate polymer to accumulate whose sedimentation constant is close to that of the polymer observed in systems inhibited by hexamethylene glycol or urea.

Thermodynamic characterization of the partially denatured states of ribonuclease A in calcium chloride and lithium chloride

1985 ◽  
Vol 63 (10) ◽  
pp. 1058-1063 ◽  
Author(s):  
Faizan Ahmad
Keyword(s):  
Calcium Chloride ◽  
Lithium Chloride ◽  
Guanidine Hydrochloride ◽  
Thermodynamic Quantity ◽  
Ribonuclease A ◽  
Ultraviolet Region ◽  
Conformational Properties ◽  
Far Ultraviolet ◽  
Denatured States

The denaturations of ribonuclease A by calcium chloride and lithium chloride were studied by circular dichroism measurements in the far-ultraviolet region. The temperature dependence of the equilibrium constant for the unfolding of the protein by calcium chloride and lithium chloride gave values of 46 and 52 kcal mol−1 (1 cal = 4.1868 J) for the enthalpy of denaturation at 25 °C and pH 7.0, respectively. Thermodynamic parameters for the denaturation by calcium chloride and lithium chloride are compared with those for the heat and guanidine hydrochloride denaturation. It has been observed that the thermodynamic quantity, be it free energy, entropy, or enthalpy, cannot be related quantitatively to the extent of unfolding measured by various conformational properties of the protein.

scholarly journals STUDIES ON THE POSTERIOR SILK GLAND OF THE SILKWORM BOMBIX MORI

1970 ◽  
Vol 46 (1) ◽  
pp. 1-16 ◽  
Author(s):  
Yutaka Tashiro ◽  
Eiichi Otsuki
Keyword(s):  
Guanidine Hydrochloride ◽  
Lithium Bromide ◽  
Posterior Part ◽  
Silk Gland ◽  
Sedimentation Equilibrium ◽  
Partial Specific Volume ◽  
Anterior Portion ◽  
Equilibrium Analyses ◽  
Fibroin Solution ◽  
Posterior Silk Gland

Ultracentrifugal analyses of the native silk proteins extracted from the various parts of the middle silk gland of the mature silkworm have revealed that there exist four components with S°20,w values of 10S, 9–10S, 9S, and 4S in the extract. It is suggested that the fastest 10S component is the native fibroin synthesized in the posterior silk gland and transferred to the middle silk gland to be stored there, while the slower three components probably correspond to inner, middle, and outer sericins which were synthesized in the posterior, middle, and anterior portion of the middle silk gland, respectively. Native fibroin solution was prepared from the most posterior part of the middle silk gland. Ultracentrifugal analyses have shown that the solution contains considerable amounts of aggregates in addition to the main 10S component. Treatment with lithium bromide (LiBr), urea, or guanidine hydrochloride solution up to 6 M all have failed to dissociate the 10S component. From the sedimentation equilibrium analyses and partial specific volume of 0.716, the molecular weight of the 10S component of the native fibroin solution was found to be between 3.2 – 4.2 x 105, with a tendency to lie fairly close to 3.7 x 105.

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