Base binding

The hide proteins differ in amino acid composition and physical stmcture. The principal amino acids (qv) of the hide proteins are hsted in Table 1. Of particular importance is the difference in the water solubiUty of the proteins. AH of the proteins are soluble in water when heated, and upon the addition of either strong acids or bases. Proteins (qv) are amphoteric, possessing both acid and base binding capacity. 

Albumen has the largest number of acid and basic groups. It is the most soluble of the proteins present in a hide. The albumen is not a fibrous material, however, and therefore has no value in the leather. Keratin is the protein of the hair and the outermost surface of the hide. Unless the hair is desired for the final product it is removed by chemical and/or physical means. The elastin has Htde acid- or base-binding capacity and is the least soluble of the proteins present. The lack of reactivity of the elastin is a detriment for most leather manufacture. The presence of elastin in the leather greatly limits the softness of the leather. 

Pizzi, A., Roll, W. and Dombo, B., United States patent USP 5,532,330. Heat-curable tannin-based binding agents. Assigned to Rutgerswerke AG, 1996. 

Probes that mediate capture of the target nucleic acid are termed capture extenders. These probes are approximately 50 bases, one portion (20 to 40 bases) of which is complementary to the target, while the second portion (approximately 20 bases) binds the probe-target complex to a capture probe that is coupled to the surface of a microtiter plate well. 

Scan of Residues in the Purine Base Binding Region... 

Competition-based Binding Site Determination and Affinity Ranking in Mixtures 1135... 

Table 4.3 Comparison of MurF ASMS screening-based binding constants and MurF activities from the radiolabeled phosphate release assay. Included from [10] with permission from SAGE Publications.

Fig. 7 also shows that base binding in the trans position weakens the metal to nitrosyl backbonding in that the Fe-NO bond length increases by 0.3 A and the Fe-N-O bond angle decreases 9°. In concert with this, the displacement of the Fe from the porphyrin plane decreases from 0.21 A in the square pyramidal structure to 0.07 A in the octahedral complex. The equilibria of NO binding to hemes is summarized in Fig. 8 [64], which indicates that NO binds to Fe" better... 

Nevin A, Cather S, Anglos D, Fotakis C (2006) Analysis of protein-based binding media found in paintings using laser induced fluorescence spectroscopy. Anal Chim Acta 573-574 341-346. 

Figure 4. A schematic depiction of the fluorescence quenching-based binding assay. The synthetic receptor is fluorescent when unbound but when die porphyrin macrocycle is forced into proximity with the Fe(III) containing heme, fluorescence is quenched. The ratio between free and bound receptor can be equated to the change in fluorescence due to protein binding.

Wang, R. X., Lai, L. H., and Wang, S. M. (2002) Further development and validation of empirical scoring functions for structure-based binding affinity prediction. J. Comput. Aided Mol. Des. 16,11-26. 

Vogtherr M, Peters T, Application of NMR based binding assays to identify key hydroxyl groups for intermolecular recognition, J. Am. Chem. Soc., 122 6093-6099, 2000. 

---