Purification et caractérisation des lectines à partir des champignons

Abstract

In this study, two fungal lectins having a lactose affinity have been purified and characterized from Lactarius deliciosus strain TME25 and Laetiporus sulphureus strain TME43 (called LDL and PSLec respectively) by different chromatographic techniques and its biological potentials were evaluated. The characterization of LDL showed that it is a heterodimeric haemagglutinin (18 and 19 kDa molecular weight for each unit), specific for galactose and methyl-α-d-galactopyranoside; affinity for lactose, fetuin and Mucin. LDL induces agglutination (ha) at temperatures below 70 ° C, and in optimal pH equal to 7. The immunomodulation assay (carbon clearance test) by LDL in vivo showed a highly significant effect of phagocyte activity of mice reticulo-endothelial system at p <0.0001. The PSLec was characterized by a homotetrameric structure of 35,904 kDa of each subunits determined by LC-MS/MS-MALDI. It is a metallodependent lectin, stable at alkali pH. In addition, the proteomic study of the mask of these peptides fragmented by the trypsin and MALDI-TOF/TOF showed us that PSLec has an identity score of 43 with the Autophagy-related protein 16 from Meyerozyma guilliermondii (ATCC strain 6260 / CBS 566 / DSM 6381 / JCM 1539 / NBRC 10279 / NRRL Y -324) (Expasy Id: ATG16_PICGU). The antimtimoral preliminary assay MTT revealed that PSLec is a cytotoxic lectin.