[5] Recently, zingibain was found to exist as two isozymes, GP-I and GP-II, which were isolated by chromatography, with molecular weights of approximately 22,500 Da.

[5] Zingibain utilizes a catalytic triad of Cys, His, and Asn residues in its active site in order to cleave peptide bonds hydrolytically.

[6] The sulfide anion then attacks the amino acid's alpha carbon, displacing the amine group, which attaches to His159.

[3] The polypeptide chain of zingibain folds into two polar domains of roughly equal size, divided by a central neutral cleft.

[3] This separation of polar and non-polar regions facilitates protein-protein interactions between the enzyme and a large range of substrates.

[1] The S2 subsite of zingibain contains the amino acid chain Trp67-Met68-Asn69-Thr133-Ala157, which makes the site too compact to accommodate larger hydrophobic aromatic substrate residues favored by other enzymes in the papain family.

Zingibain sugar sequences are almost identical to oligosaccharides seen in lectins from Japanese pagoda tree seeds, laccase a from sycamore cells, and S-glycoproteins from Brassica campestris.

It can also respond to abiotic and biotic stresses, such as heat shock, cold temperatures, and dehydration, to eliminate any resulting misfolded or denatured proteins.

The milk clotting ability and specificity of ginger protease to proteolysis of κ-casein make the enzyme a potential vegetable rennet substitute for cheese production.

The enzymes thus destabilize κ-casein micelles and encourage clumping of hydrophobic protein residues, causing milk to curdle.

[13] Fungal proteases are largely unsuitable as rennet substitutes, and enzymes from many plant extracts have been shown to produce low yields, poor textures, and bitter flavors of cheese.

[14] Zingibain has been observed to deactivate itself through autolysis, which can be pre-empted by reacting the active sulfhydryl group with cystine or PCMB.

After hydrophobic plant polyphenols are removed from crude ginger, acetone powder is introduced at low temperatures in order to dehydrate the root pulp.