Lima-bean lectin

SPARVOLIF, GALLO A, MARiNELLi D, SANTUCCi A, BOLLiNi R (1998) Novel lectin-related proteins are major components in lima bean Phaseolus lunatus L.) seeds. Biochim Biophys Acta. 1382 311-23. 

Phaseolus lunatus lectins Phaseolus lunatus (lima bean) GalNAc... 

The lima-bean agglutinin holds the distinction of being the first lectin shown to exhibit blood-group specificity. Although Boyd initially observed, in 1945, that the lima-bean lectin specifically agglutinated type A erythrocytes,2,4 he did not publish his observation until 1949,... 

Lima-bean lectin precipitated blood-group A and B secretor saliva, but not O it did not precipitate the saliva of any nonsecretors.2,3,103 Kriipe77 substantiated Boyd s results, using secretor saliva as an inhibitor of lima-bean lectin-erythrocyte agglutination. Types A,B, A,A2, AiO, and A20 saliva all inhibited the lima-bean lectin, whereas type OO saliva and type OO ovarian-cyst material were noninhibitory. 

Boyd and coworkers583 also labelled lima-bean lectin with 131I (indirectly, by coupling of [131I]-p-iodoaniline to protein by diazotization)584 and visible dyes,584,585 and quantitated the binding to type A erythrocytes. 

Ions of Mn2+ and Ca2+ were bound to the purified, lima-bean lectins.151,199 Removal of Mn2+ lowered the hemagglutination titer by 75%. (Ethylenedinitrilo)tetraacetate completely inhibited the precipitin reaction between lima-bean lectin component III and type A blood-group substance (compare Ref. 579). Several divalent-metal cations restored activity to the demetallized protein or (ethylenedinitrilo)tetraacetate-treated lectin the addition of Ca2+,... 

The specific-titer activity of lima-bean lectin components II and III towards type A human erythrocytes was 5,100 and 1,300, respectively, and, towards type B erythrocytes, 20 and 5.1, respectively.151 199 The hemagglutinating activity of component II is, thus, four times the activity151,199 of component III. Neither component reacted with type O human, red blood-cells, or native or trypsinized, rabbit erythrocytes.151,199... 

The reaction of partially purified, lima-bean lectin with hog gastric-mucin type A substance exemplified the precipitin-like curve obtained for lectin-polysaccharide or -glycoprotein reactions.103 Classical precipitin-curves between purified components II and III and type A blood-group substance were also obtained.151,199 Maximal precipitation of component II (equivalence) occurred at a lower ratio of A substance per mole of protein than for component III. Under conditions where type A substance precipitated 90% of the lectin, types A2 and B precipitated151,199 66 and 13%, respectively, of component II, and 21 and 0% of component III. Neither of the lima-bean lectins precipitated with type O blood-group substance. 

Inhibition of the precipitation reaction between lima-bean lectin component III and human blood-group A substance.587,591... 

In view of its discovery as the first blood-group-specific lectin, it is surprising that the lima-bean lectin is still one of the least studied, plant agglutinins. Undoubtedly, this lectin merits closer scrutiny. 

Papain, Bandeiraea simplicifolia lectin, and lima bean lectin have been labeled with diazotized [ I]aniline according to the procedure described... 

The carbohydrate-binding specificity of the lima bean lectin studied by inhibition of precipitation, and a sulfhydryl group protection assay [161], revealed the type A trisaccharide GalNAc(al-3)[L-Fuc(al-2)]Gal to be the best inhibitor, 40 times more potent than GalNAc. The a-glycosides of GalNAc are 8 times more potent than the corresponding 3-anomers. 

Mirelman, D., Bracha, R. Sharon, N. (1974b) Penicillin-induced Secretion of a Soluble, Uncrosslinked Peptidoglycan by Micrococcus luteus Cells Biochemistry, 13, 5045-53 Misaki, A. Goldstein, I.J. (1977) Glycosyl Moiety of Lima Bean Lectin , Journal of Biological Chemistry, 252, 6995-9... 

Legumes are a rich source of lectins or phytohemagglutinins. Inadequately cooked legumes may cause lectin-induced disturbances and adverse nutritional effect in humans. Lima bean lectin contains exposed cysteinyl groups necessary for its activity. We assessed the ability of N-acetylcysteine to act synergistically with heat in destabilizing and inactivating this lectin in lima bean flour. 

Our study IS) revealed that the cysteine derivative facilitated inactivation of lima bean lectin in the temperature range 25 to 85°C and in the pH range 4.4 to 10.0. As with the protease inhibitors described above, the beneficial action of N-acetylcysteine is postulated to involve formation of mixed disulfide bonds between the cysteine derivative, lectins, and structural proteins in the flour. 

In contrast to the findings with lima bean lectins soybean lectins which contain no cysteinyl residues, were not affected by the thiol treatments. 

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