Papaya Latex Enzyme

Antioxidant activities of gelatin hydrolysates from blacktip shark skin prepared using papaya latex enzyme with different degrees of hydrolysis (DHs: 10%, 20%, 30% and 40%) were evaluated. All antioxidant activity indices of hydrolysates increased with increasing DH (P < 0.05). When gelatin hydrolysate with 40%DH was determined for its pH and thermal stability, ORAC and chelating activity remained constant or slightly increased in a wide pH range (1–9) and during heating (100 °C) for 240 min. It was also stable in simulated gastrointestinal tract model system. Moreover, gelatin hydrolysate at a level of 500 and 1000 ppm could inhibit lipid oxidation in both β-carotene linoleate and cooked comminuted pork model systems. Therefore, gelatin hydrolysate from blacktip shark skin (40%DH) can potentially be used as an alternative source of natural antioxidants.► Gelatin hydrolysate from shark skin showed high DH (40%) when prepared using papaya latex enzyme. ► DH directly affected antioxidant activity of gelatin hydrolysate, both by chain breaking and preventive mechanisms. ► Gelatin hydrolysate retarded lipid oxidation in model systems.

Plant latex is a complex environment. Occurring in hundreds of plant species and contained in a tube system called
laticifers, latex is a milky sap with a diverse composition that includes alkaloids, terpenoid compounds, other secondary
metabolites and a number of enzymes. These substances are collectively believed to provide an important contribution to
plant defence mechanisms by repelling and killing phytopathogens, and sealing wounded areas. This review provides insights of what is currently known about the biochemistry and molecular biology of plant latex, as studied in various model systems, above all the economically important rubber tree, Hevea brasiliensis. Selecting the Mediterranean shrub Euphorbia characias as a complementary experimental model, we have recently begun to disclose the properties of several components of the enzymatic machinery present in its latex. Although the scheme of multi-enzymatic interactions taking place in the
E. characias latex depicted to date is certainly incomplete, the emerging scenario suggests that the role played by latex in plants might be significantly less passive than previously believed.

Calmodulin (CaM) is a ubiquitous Ca 2+ sensor found in all eukaryotes, where it participates in the regulation of diverse calcium-dependent physiological processes. In response to fluctuations of the intracellular concentration of Ca 2+ , CaM binds to a set of unrelated target proteins and modulates their activity. In plants, a growing number of CaM-binding proteins have been identified that apparently do not have a counterpart in animals. Some of these plant-specific Ca 2+ /CaM-activated proteins are known to tune the interaction between calcium and H 2 O 2 in orchestrating plant defenses against biotic and abiotic stresses. We previously characterized a calcium-dependent peroxidase isolated from the latex of the Mediterranean shrub Euphorbia characias (ELP) Biochemistry 42, 8909-8918].

Although severe anaphylatic reactions are rare, allergic or immediate hypersensitivity reactions to natural rubber latex (NRL) have been reported in children with increasing frequency in the last few years. Indubitably, every-day rubber has been employed in thousands and thousands of products for over a century, while recently NRL allergy has been recognized as a substantial medical problem. Children with spina bifida undergoing multiple surgical procedures, as well healthy babies, appear at high risk for NRL allergy, with life-threatening reactions reported during surgery or while playing with balloons. Skin prick testing is the preferred diagnostic method, especially in the prick by prick version. During procedures, Parents of children with latex allergy should take caution that their babies avoid contact with rubber products, and a latex-free environment. Since minimal contacts with NRL products may produce reactions, the primary treatment for latex allergy is avoidance. The cross-reactions regarding the latex-fruit syndrome have recently widened the number of possible reactions.

Here we report the cDNA nucleotide sequences of a calmodulin-binding catalase and an antiquitin from the latex of the Mediterranean shrub Euphorbia characias. Present findings suggest that catalase and antiquitin might represent additional nodes in the Euphorbia defense systems, and a multi-enzymatic interaction contributing to plant’s protection against biotic and abiotic stresses is proposed to occur in E. characias laticifers.

The changes in the heme environment and overall structure occurring during reversible thermal inactivation and in denaturant guanidinium of Euphorbia characias latex peroxidase (ELP) were investigated in the presence and absence of calcium ions. Native active enzyme had an absorption spectrum typical of a quantum-mixed spin ferric heme protein. After 40 min at 60 • C ELP was fully inactivated showing the spectroscopic behavior of a pure hexacoordinate low-spin protein. The addition of Ca 2+ to the thermally inactivated enzyme restored its native activity and its spectroscopic features, but did not increase the stability of the protein in guanidinium. It is concluded that, in Euphorbia peroxidase, Ca 2+ ion play a key role in conferring structural stability to the heme environment and in retaining active site geometry. (R. Medda). found in the cytosol, vacuole, apoplast or cell wall, and are involved in the regulation of cell growth and differentiation, cell wall lignification, metabolism of hormones and alkaloids, wound healing and defense against pathogen infection . Typically, class III peroxidases may exist under an extremely high number of isoforms within the same species, potentially implicated in different functions . For example, the peroxidase isoenzyme family of Arabidopsis thaliana comprises over 70 full-length genes, most of which predicted to encode for stable enzymes .