LinK method

Protein-Based Adhesives. Proteia-based adhesives are aormaHy used as stmctural adhesives they are all polyamino acids that are derived from blood, fish skin, caseia [9000-71 -9] soybeans, or animal hides, bones, and connective tissue (coUagen). Setting or cross-linking methods typically used are iasolubilization by means of hydrated lime and denaturation. Denaturation methods require energy which can come from heat, pressure, or radiation, as well as chemical denaturants such as carbon disulfide [75-15-0] or thiourea [62-56-6]. Complexiag salts such as those based upon cobalt, copper, or chromium have also been used. Formaldehyde and formaldehyde donors such as h exam ethyl en etetra am in e can be used to form cross-links. Removal of water from a proteia will also often denature the material. 

The cross-linking method relies on bifimctional reagents to form intermolecular linkages between the enzyme molecules to render them insoluble. Often albumin is added as an extender and glutaraldehyde is most commonly employed. This material can then be either formed as a free standing membrane or applied to the inner surface of the dialysis membrane... 

Brunner J. (1993) New photolabeling and cross-linking methods. Annu. Rev. Biochem. 62, 483-514. 

Hamada, H., and Tsuro, T. (1987) Determination of membrane antigens by a covalent cross-linking method with monoclonal antibodies. Anal. Biochem. 160, 483-488. 

Orlando, V., Strutt, H., and Paro, R. (1997) Analysis of chromatin structure by in vivo formaldehyde cross-linking. Methods 11, 205-214. 

Scheme 2.4 Polymer support silylene linking method for hindered hydroxyl-bearing glycals.

The second approach used for linking clusters is termed the centroid link method. This method joins the centroids of the clusters instead of the nearest neighbors. The centroid is calculated as the average of the points within a cluster. Clustering using this approach with the same data as in Figure 4.8 is shown in Figure 4.10. 

The single and centroid linking methods do not always join clusters in. the same order as in the previous example. Figure 4.12 shows an example where these methods yield different dendrograms. If the single-link method is used, the clustering proceeds as follows (solid lines in Figure 4.12) ... 

This results in the dendrogram foimd in Figure 4.13 2- If the centroid-link method is used on these same data, the clustering scheme is as follows (dashed lines in Figure 4.12) ... 

Yunoki, S., Suzuki, T., and Takai, M. (2003). Stabilization of low denaturation temperature collagen from fish by physical cross-linking methods. J. Biosci. Bioeng. 96, 575-577. 

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