The botanist Vines believed that he was able to separate both peptone-forming and peptone-splitting enzymes from the milky sap of Carica papaya (1). Applying quantitative methods to the hydrocyanic acid activation of papain, Willstatter and Grassmann (2) concluded that papain is a homogeneous enzyme. They assumed that hydrocyanic acid plays the role of a kinase that extends the specificity rang...

Papain has long been known to cause the gelation of mammalian fibrinogens. It has also been reported that papain-fibrin is insoluble in dispersing solvents like strong urea or sodium bromide solutions, similar to what is observed with thrombin-generated clots in the presence of factor XIIIa and calcium. In those old studies, both the gelation and subsequent clot stabilization were attributed to...

Papain (EC.3.4.22.2) is a cysteine proteinase extracted from the plant, Curicupupayu, which is used extensively in many industrial processes, due to its high stability and broad substrate range. The enzyme consists of a single polypeptide chain of 212 residues and has a molecular weight of 23,400 daltons [l]. The three dimensional structure has been determined to high resolution, and shows that...

The effect of papain treatment on the cartilage tissue of the knee joint of mature rabbits was studied by histological and thermoanalytical methods. Changes taking place in the composition of cartilage in the course of ageing were shown. As a result of papain treatment a significant irreversible destruction of the ground substance took place. Papain-induced loss of proteoglycans and the intensi...

A method for immobilization of papain has been selected based on the interaction between its histidine, cysteine and tryptophan residues with the immobilized metal ion (IMI) carrier for maximum binding on a small volume of the carrier. The immobilized papain retained high activity has improved thermal stability and the carrier could be recovered from the spent bound enzyme, to be reused. Reimmo...

Studies on a number of cysteine proteinases of the papain (EC 3.4.22.2) family using pyridyland pyrimidyldisulphide reactivity probes have demonstrated that the catalytic site (Cys)-S-/(His)-Im+H ion-pair states of these enzymes are produced at low pH where the enzymes are inactive and that catalytic competence is generated by protonic dissociation across pKa 4 [ 1-41. The assignment of the pKa...

Membrane-based bioreactors can greatly influence the rate and extent of chemical reactions and consequently lower the costs associated with the corresponding engineering processes. However, in order to progress in this area, greater understanding of the relationship of the structure and function of bioreactor systems is required. In this study, a proteolytic enzyme, papain (EC 3.4.22.2), was co...

The cleavage into large fragments of both normal and immune rabbit y-globulin by cysteine-activated papain was reported by Porter (1, 2). In the case of immune y-globulin the antibody activity was found associated with two of the three principal fragments isolated. Nisonoff et al. (3) have carried out the cleavage of rabbit immune y-globulin into similar fragments with a sedimentation constant ...

Living tadpoles and Arbacia eggs are not digested by ficin or papain although the dead organisms are. Arbacia eggs develop in papain solutions but the cells become separated. Development is normal in ficin and trypsin solutions.

Succinyl-Gln-Val-Val-Ala-Ala-p-nitroanilide corresponding to a common sequence of endogenous thiol protease inhibitors is a noncompetitive reversible inhibitor of papain. In order to elucidate the binding mode of the inhibitor at the atomic level, its complex with papain was crystallized at ca. pH 7.0 using the hanging drop method, and the crystal structure was analyzed at 1.7-A resolution. The...