Isoelectric point

Tyrosine containing conjugated double bonds, tryptophan (280nm)

Produces blue-violet compound (570nm)

Protects the sulfhydryl groups in proteins and enzymes in the body from oxidation and is active

Reduce H2O2 in the body to H2O

Sulfhydryl groups have nucleophilic properties and protect the body from toxic effects

Peptide and disulfide bonds

hydrogen bond

Secondary bond (alienated hydrogen)

Leucine zipper, zinc finger structure

Hydrogen ion

positive synergy

allosteric effect

Alzheimer's disease, Huntington's disease, mad cow disease

Surface charges and hydration films maintain protein stability

Under physical and chemical factors, the specific spatial structure is destroyed, and the physical and chemical properties and biological activity are lost.

Reduced solubility, increased viscosity, loss of crystallization ability, loss of biological activity, and easy hydrolysis by proteases

Ninhydrin reaction

biuret reaction