Isolation and partial characterization of 3 nontoxic d‐galactose–specific isolectins from seeds of Momordica balsamina

Abstract

Three isolectins denoted hereforth MBaL-30, MBaL-60, and MBaL-80 were isolated from seeds extract of Momordica balsamina by 30%, 60%, and 80% ammonium sulfate saturations, respectively. The native molecular weights of these lectins, as judged by gel filtration, were 108, 56, and 160 kDa, respectively. On SDS-PAGE, under reduced condition, 27 kDa band was obtained for all isolectins. The lectins hemagglutinating activities were variably inhibited by d-galactose (minimum inhibitory concentrations = 12.5mM, 50mM, and 0.391mM, respectively). MBaL-30 and -60 could agglutinate all human blood types with slight preference for the A and O blood groups, whereas MBaL-80 did not agglutinate B and AB blood types. The 3 isolectins were purified from crude seeds extract, collectively, in a single step on the affinity matrix Lactamyl-Seralose 4B; this purified lectin fraction, which contains all isolectins, is termed MBaL. The N-terminal of MBaL till the 25th amino acid was NLSLSELDFSADTYKSFIKNLRKQL, which shares 88% sequence identity with Momordica charantia lectin type-2 ribosomal inactivating protein from Momordica charantia and 50% with momordin II from Momordica balsamina. MBaL retained 100% activity at up to 50°C for 30 minutes. MBaL-30 and MBaL-60 exhibited maximum activities in the pH range between 4 and 8, while MBaL-80 was showing maximum activity in the pH range between 3 and 5. Treatment of MBaL-30 and MBaL-60 with EDTA completely abolished their hemagglutinating activities. Addition of Zn and Fe ions to the ethylenediaminetetraacetic acid-treated MBaL-30 and MBaL-60 lectins did not only regained the loss of activity but also resulted in 200% to 300% increase in activity, respectively. MBaL-30 and -60 agglutinated gram positive Listeria monocytogenes and Staphylococcus aureus, whereas MBaL-30 could merely agglutinate Escherichia coli. None of these lectins could arrest bacterial growth. Addition of MBaL to cancer cell lines (Gastric cancer cell line (AGS) and Gastric cencer cell line (MKN45), Glioblastoma (ECV-304), and Human urinary bladder cancer cell line (U87-MG)) at varying concentrations did not cause statistically significant changes on cell growth and viability.

Purification, Partial Characterization, and Evaluation of the Antiulcer Activity of Calotropis procera Leaf Lectin

“…When Athrone solution was added to 200 µg ProLec an intense blue colour was produced indicating the glycoprotein nature of the lectin. Even though the majority of plant lectins are glycosylated [ 4 , 23 ], few are nonglycosylated like concanavalin A (ConA) and Peanut ( Arachis hypogaea ) seeds lectin [ 33 , 34 ].…”

“…Hemagglutination unit is expressed as titre, i.e. , the highest lectin dilution that would still give visible hemagglutination [ 23 ].…”

Isolation of Jatropha Curcas Seeds Isolectins with Variable Affinity for Human and Animal Blood Types

“…Hemagglutinating activity was expressed as titer, namely, the reciprocal of the highest dilution that gave a clear agglutination. The specific hemagglutinating activity was defined as titer (unit) per mg protein [12,13].…”

Genome-wide screening of lectin putative genes from Sorghum bicolor L., distribution in QTLs and a probable implications of lectins in abiotic stress tolerance

“…This allows lectin homologs that belong to the same family to function in diverse physiological pathways [28][29][30]. Despite the wealth of information about plant lectins in terms of physicochemical, structural, expressional, and genomic studies, as well as their possible application [31][32][33][34], there had been no attempt to isolate and study sorghum lectins. To the best of our knowledge, only a single study was published in 1982; where seed lectins from 5 sorghum species were isolated and marginally characterized with respect to blood and sugar specificity only [35].…”