Proteins hydrazide derivatives

Figure 1.109 Carboxylate groups on proteins may be modified with adipic acid dihydrazide in the presence of a carbodiimide to produce hydrazide derivatives.

Aldehyde particles are spontaneously reactive with hydrazine or hydrazide derivatives, forming hydrazone linkages upon Schiff base formation. Reactions with amine-containing molecules, such as proteins, can be done through a reductive amination process using sodium cyanoborohydride (Figure 14.21). 

Of the twenty-five compounds screened, the 2-substituted histidine analogues (201)-(203), together with a-methyl-L-histidine (206) and the hydrazide derivative (207) were found to inhibit P. falciparum growth and protein synthesis at 1.0 mM, while the 2-fluoro (202) and 2-iodo (203) analogues were also inhibitory at 0.125 mM, compound (202) proving the most potent of the compoimds evaluated. Unfortunately, 2-bromo-L-histidine and 2-chloro-L-histidine (204) and (205) were not available for comparison with the 2-azido amino-acid (201). The exact mechanism of... 

Most proteins contain an abundance of carboxylic acid groups from C-terminal functionalities and aspartic and glutamic acid side chains. These groups are readily modified with bis-hydrazide compounds to yield useful hydrazide-activated derivatives. Both carbohydrazide and adipic acid dihydrazide have been employed in forming these modifications using the carbodi-imide reaction (Wilchek and Bayer, 1987). 

Hydrazide groups react with aldehyde and ketone groups to form hydrazone linkages (Chapter 2, Section 5.1). Three BODIPY derivatives are available that contain a hydrazine group modification of carboxylate side chains. Biomolecules such as proteins that don t normally possess aldehyde residues can be modified to contain them by a number of chemical means (Chapter 1, Section 4.4). 

Figure 17.4 Ketone derivatives of phenylalanine and mannose can be fed to cells to incorporate the monomers into proteins and glycans. The resultant modifications can be probed using hydrazide-containing reagents.

Hydrazide groups can react with carbonyl groups to form stable hydrazone linkages. Derivatives of proteins formed from the reaction of their carboxylate side chains with adipic acid dihydrazide (Chapter 4, Section 8.1) and the water-soluble carbodiimide EDC (Chapter 3, Section 1.1) create activated proteins that can covalently bind to formyl residues. Hydrazide-modified enzymes prepared in this manner can bind specifically to aldehyde groups formed by mild periodate oxidation of carbohydrates (Chapter 1, Section 4.4). These reagents can be used in assay systems to detect or measure glycoproteins in cells, tissue sections, or blots (Gershoni et al., 1985). 

Schwartz, D.A., Abrams, M.J., Giadomenico, C.M., and Zubieta, J.A. (1995) Protein labelling utilizing certain pyridyl hydrazines, hydrazides and derivatives. US Patent No. 5,420,285. 

Time Succinimidyl ester derivatives will react with a protein within 1 h. Periodate oxidation will require 2 h at pH 6.0. Reaction with biotin hydrazide can be performed in a few hours. Stabilization with cyanoboro-hydride... 

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