Simultaneous allergen inactivation and detoxification of castor bean cake by treatment with calcium compounds

Ricinus communis L. is of great economic importance due to the oil extracted from its seeds. Castor oil has been used for pharmaceutical and industrial applications, as a lubricant or coating agent, as a component of plastic products, as a fungicide or in the synthesis of biodiesel fuels. After oil extraction, a castor cake with a large amount of protein is obtained. However, this by-product cannot be used as animal feed due to the presence of toxic (ricin) and allergenic (2S albumin) proteins. Here, we propose two processes for detoxification and allergen inactivation of the castor cake. In addition, we establish a biological test to detect ricin and validate these detoxification processes. In this test, Vero cells were treated with ricin, and cell death was assessed by cell counting and measurement of lactate dehydrogenase activity. The limit of detection of the Vero cell assay was 10 ng/mL using a concentration of 1.6 x 10(5) cells/well. Solid-state fermentation (SSF) and treatment with calcium compounds were used as cake detoxification processes. For SSF, Aspergillus niger was grown using a castor cake as a substrate, and this cake was analyzed after 24, 48, 72, and 96 h of SSF. Ricin was eliminated after 24 h of SSF treatment. The cake was treated with 4 or 8% Ca(OH)2 or CaO, and both the toxicity and the allergenic properties were entirely abolished. A by-product free of toxicity and allergens was obtained.

Isolation and intracellular localization of insulin-like proteins from leaves of Bauhinia variegata

Evidence based on immunological cross-reactivity and anti-diabetic properties has suggested the presence of insulin-like peptides in plants. The objective of the present study was to investigate the presence of insulin-like proteins in the leaves of Bauhinia variegata ("pata-de-vaca", "mororó"), a plant widely utilized in popular medicine as an anti-diabetic agent. We show that an insulin-like protein was present in the leaves of this plant. A chloroplast protein with a molecular mass similar to that of bovine insulin was extracted from 2-mm thick 15 percent SDS-PAGE gels and fractionated with a 2 x 24 cm Sephadex G-50 column. The activity of this insulin-like protein (0.48 mg/mL) on serum glucose levels of four-week-old Swiss albino (CF1) diabetic mice was similar to that of commercial swine insulin used as control. Further characterization of this molecule by reverse-phase hydrophobic HPLC chromatographic analysis as well as its antidiabetic activity on alloxan-induced mice showed that it has insulin-like properties. Immunolocalization of the insulin-like protein in the leaves of B. variegata was performed by transmission electron microscopy using a polyclonal anti-insulin human antibody. Localization in the leaf blades revealed that the insulin-like protein is present mainly in chloroplasts where it is also found associated with crystals which may be calcium oxalate. The presence of an insulin-like protein in chloroplasts may indicate its involvement in carbohydrate metabolism. This finding has strengthened our previous results and suggests that insulin-signaling pathways have been conserved through evolution.

A protein with amino acid sequence homology to bovine insulin is present in the legume Vigna unguiculata (cowpea)

Since the discovery of bovine insulin in plants, much effort has been devoted to the characterization of these proteins and elucidation of their functions. We report here the isolation of a protein with similar molecular mass and same amino acid sequence to bovine insulin from developing fruits of cowpea (Vigna unguiculata) genotype Epace 10. Insulin was measured by ELISA using an anti-human insulin antibody and was detected both in empty pods and seed coats but not in the embryo. The highest concentrations (about 0.5 ng/æg of protein) of the protein were detected in seed coats at 16 and 18 days after pollination, and the values were 1.6 to 4.0 times higher than those found for isolated pods tested on any day. N-terminal amino acid sequencing of insulin was performed on the protein purified by C4-HPLC. The significance of the presence of insulin in these plant tissues is not fully understood but we speculate that it may be involved in the transport of carbohydrate to the fruit

Lima bean (Phaseolus lunatus) seed coat phaseolin is detrimental to the cowpea weevil (Callosobruchus maculatus)

The presence of phaseolin (a vicilin-like 7S storage globulin) peptides in the seed coat of the legume Phaseolus lunatus L. (lima bean) was demonstrated by N-terminal amino acid sequencing. Utilizing an artificial seed system assay we showed that phaseolin, isolated from both cotyledon and testa tissues of P. lunatus, is detrimental to the nonhost bruchid Callosobruchus maculatus (F) (cowpea weevil) with ED50 of 1.7 and 3.5 percent, respectively. The level of phaseolin in the seed coat (16.7 percent) was found to be sufficient to deter larval development of this bruchid. The expression of a C. maculatus-detrimental protein in the testa of nonhost seeds suggests that the protein may have played a significant role in the evolutionary adaptation of bruchids to legume seeds

An allergenic 2S storage protein from ricinus communis seeds which is a part of the 2s albumin precursor predicted by C-DNA data

A 1.9s albumin having allergenic activity and denoted Ric c III was isolated from an alcohol extract of defatted Ricinus communis seeds CB-1A, as a homogeneous protein by ion -exchange chromatography on SP-Sephadex, gel filtration on Sephadex G-75 and preparative polyacrylamide gel electrophoresis (6 mg Ric cIII/g CB-1A). The protein contained approximately 98 amino acid residues distributed in 2 chains of 67 anmd 34 residues, a molecular weight of 11.239 based on amino acid composition and pI=4.9 Ric c III can be aligned, on the basis of amino acid composition and partial amino acid sequence data, with residues 18 to 50 (51) and 66 to 130 of the 2S albumin precursor predicted by the cDNA data of S. D. Irwin, J. N. Ken, J. B. C. Findlary and J. M. Lord (Molecular and General Genetics, 222:400-408, 1990). The present data identify Ric c III as the second allergenic 2S storage albumin coded by this DNA

Isolation and partial characterization of antigen 5.1 from the seeds of Ricinus communis, L. (var. amarelo de irece)

Antigen 5.1 was isolated from the most acidic fraction of castor bean allergens (CB-1A) by gel filtration on Sephadex G-75 followed by polyacrylamide gel electrophoresis (PAGE) (yield: 6.2 mg antigen 5.1/g CB-1A). This antigen was homogeneous by the criteria of PAGE, isoelectric focusing, SDS-PAGE, immunoelectrophoresis and gel filtration. The antigen has an apparent molecular mass of 12 ñ 2 kDa and an isoelectric point of pH 5.1. Antigen 5.1 lacks proline, phenylalanine, threonine and tryptophan. It was immunochemically identical to one of the three immunoprecipitation lines presented by CB-1A by the Ouchterlony technique, and was positive when tested (250 *g) by IgE-mediated passive cutaneous anaphylaxis in LOU.M rats

Structural studies on allergen RC-13 from Ricinus communis L.: isolation and characterization of a major glycopeptide

A glycoprotein, RC-13, isolated from Ricinus communis seeds was reduced, S-alkylated and cleaved by trypsin. The tryptic digest was fractionated by ion-exchange chromatography and a glycopeptide was isolated and purified by high-voltage paper electrophoresis. When submitted to amino acid and carbohydrate analyses this major glycopeptide showed the following chemical composition: Lys1, Asp1, Thr2, Ser4, Glu1, Pro2, Gly2, Ala2, Val2, GlcN6, Man6 and Gal8. Hydrazynolysis positioned Ser as the C-terminal residue. It is postulated that this glycopeptide belongs to the C-terminal region of the allergen