scholarly journals A lectin from the exudate of the fruit of the vegetable marrow (Cucurbita pepo) that has a specificity for β-1,4-linked N-acetylglucosamine oligosaccharides

1979 ◽  
Vol 183 (1) ◽  
pp. 133-137 ◽  
Author(s):  
A K Allen

Lectins are present in the exudate (presumably from the phloem) of the fruits of three species of the Cucurbitaceae, namely vegetable marrow (Cucurbita pepo), melon (Cucumis melo) and cucumber (Cucumis sativus). They are all strongly inhibited in their activities by chitin oligosaccharides, but only weakly by N-acetylglucosamine. Glycopeptides from soya-bean agglutinin and fetuin are also strong inhibitors of Cucurbita pepo lectin, indicating that it interacts with internal N-acetylglucosamine residues. The lectin from Cucurbita pepo fruit was purified by affinity chromatography by using chitin oligosaccharides covalently attached to Sepharose. The lectin is not a glycoprotein, and it consists of a single polypeptide chain of about 20,000 mol.wt. It is a major protein (18% of the total) of the phloem exudate and it is postulated that it may have an anti-parasitic function.

FEBS Letters ◽  
1975 ◽  
Vol 58 (1-2) ◽  
pp. 181-185 ◽  
Author(s):  
Edna J. Bates ◽  
Gillian M. Heaton ◽  
Carol Taylor ◽  
John C. Kernohan ◽  
Philip Cohen

1979 ◽  
Vol 254 (14) ◽  
pp. 6240-6243 ◽  
Author(s):  
G C DuBois ◽  
E Appella ◽  
R Armstrong ◽  
W Levin ◽  
A Y Lu ◽  
...  

1985 ◽  
Vol 162 (3) ◽  
pp. 1044-1059 ◽  
Author(s):  
C M Sorensen ◽  
R J Hayashi ◽  
C W Pierce

Hyperimmunization of BALB/c mice with concanavalin A-stimulated blasts from the Ig allotype-congenic strain, C.B20, results in the production of antibodies reactive with T cells in an allotype-restricted manner. Spleen cells from these hyperimmune BALB/c mice were used to generate a panel of hybridomas that secrete monoclonal antibodies, reactive, in an allotype-restricted manner, exclusively with T cells subpopulations, and in particular, reactive with suppressor T cell hybridomas and their secreted soluble factors. Two functional classes of antibodies were identified: those that react with single polypeptide-chain suppressor T cell factors (TsF1) and the suppressor T cell hybridomas that produce such factors, and those that react with two polypeptide-chain suppressor T cell factors (TsF2) and their corresponding suppressor T cell hybridomas. These two classes of antibody were used to isolate molecules from the membranes of the respective suppressor T cell hybrids that are functionally and structurally related to the secreted suppressor T cell factors, suggesting a receptor function for these molecules.


2018 ◽  
Vol 2 (5) ◽  
pp. 681-686 ◽  
Author(s):  
Jaime Andrés Rivas-Pardo

Titin — the largest protein in the human body — spans half of the muscle sarcomere from the Z-disk to the M-band through a single polypeptide chain. More than 30 000 amino acid residues coded from a single gene (TTN, in humans Q8WZ42) form a long filamentous protein organized in individual globular domains concatenated in tandem. Owing to its location and close interaction with the other muscle filaments, titin is considered the third filament of muscle, after the thick-myosin and the thin-actin filaments.


1974 ◽  
Vol 143 (2) ◽  
pp. 257-264 ◽  
Author(s):  
Michael D. Scawen ◽  
Donald Boulter

The amino acid sequence of plastocyanin from marrow was determined. It consists of a single polypeptide chain of mol.wt. 10284 containing 99 amino acid residues. The sequence was determined by using a Beckman 890C automatic sequencer and by dansyl–phenyl isothiocyanate analysis of peptides obtained by the enzymic digestion of purified CNBr fragments. The sequence is in good agreement with the amino acid composition, except that fewer residues of glutamic acid were found in the sequence than were suggested by the composition. Evidence for histidine-37 was weaker than for the rest of the sequence. A ‘tree’ of phylogenetic affinities was constructed by using several higher-plant plastocyanin sequences.


1978 ◽  
Vol 174 (2) ◽  
pp. 497-502 ◽  
Author(s):  
J C Cox ◽  
D H Boxer

The ‘blue’ copper-containing protein rusticyanin was purified to homogeneity from cells of the chemolithotrophic bacterium Thiobacillus ferro-oxidans by (NH4)SO4 fractionation and ion-exchange chromatography. The protein, which is stable at low pH, consists of a single polypeptide chain of mol. wt. 16500 and possesses 0.79 (+/- 0.28)g-atom of Cu/mol. The protein, which does not contain arginine residues, has optical absorbance maxima at 287, 450, 597 and 750 nm and is generally similar to azurin. The isolated protein is reduced directly by Fe2+ with a 1:1 stoicheiometry to Cu. On reduction by Fe2+ the absorption peaks at 450, 597 and 750 nm are abolished, with the appearance of a new absorption band at 320 nm. The results obtained are consistent with rusticyanin being the initial acceptor of electrons from Fe2+ during respiratory iron oxidation.


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