A Mitogenic Protein Fraction in Latex from Carica candamarcensis

Abstract

Latex from Caricaceae contains a number of proteins believed to be part of a defense mechanism that protects these plants from wounding. Prior evidence suggests that some components in Carica papaya improve healing of ulcerous wounds in mammals. This study shows the chromatographic isolation of a protein fraction from C. candamarcensis that stimulates cell proliferation of mammalian cells by measuring MTT reduction and thymidine incorporation. The effect appears to be cell specific as L929, MDA-MB231 and BHK-21 cells are stimulated while no effect is seen on CHO cells. The maximal stimulatory effect reaches 2.2-fold 72 h after addition of the active fraction to L929, 1.8-fold in MDA-MB231 cells and 1.6-fold in BHK cells. Proteolytic inactivation of the active fraction suggests that a protein is responsible for the proliferative activity and its size is estimated between 10 and 25 kDa. A potential candidate for this function is a 23 kDa protein found in the fraction that reacts with human EGF antibody.

Key words

Latex - mitogen - Caricaceae - Carica candamarcensis

References

• 1 Farrel B D, Dussourd D E, Mitter C. Escalation of plant defense: do latex and resin canals spur plant diversification?.  Am Nat. 1991;  138 881-900
• 2 Joel D M. Resin ducts in the mango fruit: a defense system.  J Exp Bot. 1980;  31 1707-18
• 3 Dussourd D , Eisner T. Vein-cutting behavior: insect counterploy to the latex defense of plants.  Science. 1987;  237 898-901
• 4 Furie B, Furie B C. The molecular base of blood coagulation.  Cell. 1988;  53 505-18
• 5 Silva L G, Garcia O, Lopes M TP, Salas C E. Changes in protein profile during coagulation of latex from Carica papaya .  Braz J Med Biol Res. 1997;  30 615-9
• 6 Moutim V, Silva L G, Lopes M TP, Fernandes G W, Salas C E. Spontaneous processing of peptides during coagulation of latex from Carica papaya .  Plant Sci. 1999;  142 115-21
• 7 Clarck R AF. The molecular and cellular biology of wound repair, Second edition. edited Clarck RAF Plenum Press New York; 1998
• 8 Kohorn B D, Lane S, Smith T A. An Arabidopsis serine/threonine kinase homologue with an epidermal growth factor repeat selected in yeast selected for its specificity for a thylakoid membrane protein.  PNAS. 1992;  89 10 989-92
• 9 Bravo L M, Hermosilla L, Salas C E. A biochemical comparison between latex from C. candamarcensis and C. papaya .  Braz J Med Biol Res. 1994;  27 2831-42
• 10 Pereira M T, Lopes M TP, Meira W O, Salas C E. Purification of a cysteine proteinase from Carica candamarcensis L. and cloning of a genomic putative fragment coding for this enzyme.  Protein Express Purif. 2001;  22 249-57
• 11 Baeza G, Correa D, Salas C E. Proteolytic enzymes in C. candamarcensis .  J Sci Food and Agric. 1990;  51 1-9
• 12 Gravina de Moraes M, Termignoni C, Salas C E. Biochemical characterization of a new cysteine endopeptidase from Carica candamarcensis L.  Plant Sci. 1994;  102 11-8
• 13 Lowry O H, Rosebrough N J, Farr A L, Randall R J. Protein measurement with the Folin phenol reagent.  J Biol Chem. 1951;  193 265-75
• 14 Laemmli U K. Protein electrophoresis in slab Gels.  Nature. 1970;  227 680-3
• 15 Scudeiro D A, Shoemaker R H, Paull K D. Evaluation of a soluble tetrazolium formazan for cell growth and drug sensitivity in culture using human and other tumor cell lines.  Cancer Research. 1988;  48 4827-33
• 16 Armelin M CS, Gambarini A G, Armelin H A. On the regulation of DNA synthesis in a line of adrenocortical tumor cells: effect of serum, adrenocorticotropin and pituitary factors.  J Cell Physiol. 1977;  93 1-9
• 17 Pimentel E. In Handbook of growth factors: Peptide growth factors. Edited by Pimentel E CRC Press Boca Raton; 1994 vol. 2: pp. 97-186
• 18 Polet H. Epidermal growth factor stimulates DNA synthesis while inhibition cell multiplication of A-431 carcinoma cells.  Exp Cell Res. 1990;  186 390-3
• 19 Mynott T L, Ladhams A, Scarmato P, Engwerda C R. Bromelain from pineapple stems, proteolytically blocks activation of extracellular regulated kinases-2 in T cells.  J Immunol. 1999;  163 2568-75
• 20 Komatsu S, Abe K, Karibe H. Epidermal growth factor binding proteins in rice.  Biol Pharm Bull. 1996;  19 905-8
• 21 Hewitt H, Whittle S, Lopez S, Bailey E, Weaver S. Topical use of papaya in chronic skin ulcer therapy in Jamaica.  West Indian Med J. 2000;  49 32-3