Alteration of quaternary structure and biological activity of concanavalin A

1984 ◽  
Vol 3 (1) ◽  
pp. 63-71 ◽  
Author(s):  
Shin-ichi Ishii ◽  
Yukichi Abe ◽  
Isao Tanaka ◽  
Masaki Saito
Keyword(s):  
Biological Activity ◽  
Concanavalin A ◽  
Quaternary Structure

scholarly journals A computergraphical method of describing the shapes of subunit interfaces of oligomers. Analysis of the quaternary structure of concanavalin A and of prealbumin

1982 ◽  
Vol 205 (2) ◽  
pp. 353-359 ◽  
Author(s):  
E J Milner-White
Keyword(s):  
Concanavalin A ◽  
Quaternary Structure ◽  
Beta Sheets ◽  
New Method

A new method is described for mapping the shape of the intersubunit contacts of oligomers with identical subunits or pairs of subunits. Plots are generated for the dimer-dimer interactions of concanavalin A and prealbumin, which are both tetramers. Both contacts lie at the junction between the faces of two apposed beta-sheets, but in most other respects the interactions are seen to be different.

Carbodiimide-mediated conjugation of hippuric acid to concanavalin A: retention of ligand binding and hemagglutinating activities

1986 ◽  
Vol 64 (12) ◽  
pp. 1366-1371 ◽  
Author(s):  
James F. Preston III ◽  
Ronald S. Hencin
Keyword(s):  
Biological Activity ◽  
Reaction Time ◽  
Ligand Binding ◽  
Small Molecules ◽  
Concanavalin A ◽  
Hippuric Acid ◽  
Carboxyl Groups ◽  
Cross Linking ◽  
Amino Groups ◽  
Hemagglutination Titer

Conditions for conjugating small molecules with reactive carboxyl groups to concanavalin A (ConA), with retention of biological activity of the lectin, are described. Hippuric acid was conjugated to reactive amino groups on ConA with N-ethyl-N′-(dimethylaminopropyl)carbodiimide under conditions in which neither inter- nor intra-molecular cross-linking was detectable. These same conditions provided for the loading of variable amounts of hippurate as a function of reaction time; conjugates were synthesized with 9.6 mol hippurate∙mol ConA−1. Conjugation in the presence of 0.1 M phosphate provided a condition for limiting the extent of coupling; only amide linkages were formed. These conjugates retained both the ability to bind ligands and the hemagglutination titer of the native lectin.

Effects of oestradiol-17β and LRH upon the two fractions of pituitary follicle-stimulating hormone separated by concanavalin-A chromatography

1985 ◽  
Vol 110 (4) ◽  
pp. 475-482
Author(s):  
Alfredo Ulloa-Aguirre ◽  
Emma Torra ◽  
Roberto Domínguez ◽  
Robert Scherpbier ◽  
Fernando Larrea
Keyword(s):  
Biological Activity ◽  
Concanavalin A ◽  
Anterior Pituitary ◽  
Follicle Stimulating Hormone ◽  
Exposure Condition ◽  
Con A ◽  
Ovx Rats ◽  
Intact Rats ◽  
Stimulating Hormone

Abstract. The effects of oestradiol-17β (E2) and LRH upon the two fractions of pituitary follicle stimulating hormone (FSH) obtained by concanavalin A (Con A) chromatography were studied. Anterior pituitary glands were removed from adult intact rats at different times throughout the oestrous cycle, and from long-term ovariectomized (Ovx) rats after specific endocrine treatments. The presence, relative ratio and biological activity of each Con A separable FSH fraction were assessed by a specific radioimmunoassay and by an in vitro bioassay. After separation by concanavalin A chromatography, glands from intact rats sacrificed during the days of oestrus, dioestrus 1 and dioestrus 2, exhibited constant relative ratios (U:B FSH ratio) of the two FSH fractions so separated (Con A unbound and bound FSH), whereas donors sacrificed at the morning and early afternoon (13.00– 15.00 h) of the day of pro-oestrus, showed the highest U:B FSH ratio; this ratio abruptly declined at the time of the FSH surge, after 15.00 h of pro-oestrus. Ovx rats exhibited lower ratios than intact animals. Pituitary extracts from Ovx donors under short-term (20 h) E2 exposure (condition which decreased pituitary sensitivity to LRH), showed the lowest U:B FSH ratio, whereas glands from Ovx rats exposed to conditions which caused increased pituitary LRH exposure (immediately before the oestradiol-induced FSH surge or after injection of 100 ng of LRH) showed an increase in their U:B FSH ratio, as compared with Ovx and Ovx + E2 (20 h) rats. Ovx animals exposed to oestradiol (during 33 h), phenobarbitone (at 30 h) and 200 ng of LRH (at 31 h), exhibited a dramatic decrease in the pituitary content of the Con A unbound FSH fraction, similar to that shown in intact rats during the late afternoon of pro-oestrus. Both FSH fractions exhibited similar in vitro biological activity and apparent molecular weight. These studies demonstrate that the existing endocrine milieu regulates the carbohydrate content and/or arrangement of the FSH molecule, and hence, the type of FSH produced by the anterior pituitary gland.

scholarly journals ConA-Like Lectins: High Similarity Proteins as Models to Study Structure/Biological Activities Relationships

2018 ◽  
Vol 20 (1) ◽  
pp. 30 ◽  
Author(s):  
Benildo Cavada ◽  
Vanir Pinto-Junior ◽  
Vinicius Osterne ◽  
Kyria Nascimento
Keyword(s):  
Biological Activity ◽  
Structural Properties ◽  
Concanavalin A ◽  
Biological Activities ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Carbohydrate Specificity ◽  
High Similarity ◽  
Antitumor Activities ◽  
Reversible Binding

Lectins are a widely studied group of proteins capable of specific and reversible binding to carbohydrates. Undoubtedly, the best characterized are those extracted from plants of the Leguminosae family. Inside this group of proteins, those from the Diocleinae subtribe have attracted attention, in particular Concanavalin A (ConA), the best-studied lectin of the group. Diocleinae lectins, also called ConA-like lectins, present a high similarity of sequence and three-dimensional structure and are known to present inflammatory, vasoactive, antibiotic, immunomodulatory and antitumor activities, among others. This high similarity of lectins inside the ConA-like group makes it possible to use them to study structure/biological activity relationships by the variability of both carbohydrate specificity and biological activities results. It is in this context the following review aims to summarize the most recent data on the biochemical and structural properties, as well as biological activities, of ConA-like lectins and the use of these lectins as models to study structure/biological activity relationships.

Quaternary structure of Limulus polyphemus hemocyanin

1978 ◽  
Vol 36 (2) ◽  
pp. 176-177
Author(s):  
T. Wichertjes ◽  
E.J. Kwak ◽  
E.F.J. Van Bruggen
Keyword(s):  
Electron Microscopy ◽  
Functional Properties ◽  
Horseshoe Crab ◽  
Temperature Jump ◽  
Quaternary Structure ◽  
Crystallographic Analysis ◽  
Limulus Polyphemus ◽  
Oxygen Binding ◽  
X Ray ◽  
Intact Molecule

Hemocyanin of the horseshoe crab (Limulus polyphemus) has been studied in nany ways. Recently the structure, dissociation and reassembly was studied using electron microscopy of negatively stained specimens as the method of investigation. Crystallization of the protein proved to be possible and X-ray crystallographic analysis was started. Also fluorescence properties of the hemocyanin after dialysis against Tris-glycine buffer + 0.01 M EDTA pH 8.9 (so called “stripped” hemocyanin) and its fractions II and V were studied, as well as functional properties of the fractions by NMR. Finally the temperature-jump method was used for assaying the oxygen binding of the dissociating molecule and of preparations of isolated subunits. Nevertheless very little is known about the structure of the intact molecule. Schutter et al. suggested that the molecule possibly consists of two halves, combined in a staggered way, the halves themselves consisting of four subunits arranged in a square.

Characterization of Tamm-Horsfall Urinary Glycoprotein

1973 ◽  
Vol 31 ◽  
pp. 420-421
Author(s):  
John P. Robinson ◽  
J. David Puett
Keyword(s):  
Electron Microscopy ◽  
Circular Dichroism ◽  
Secondary Structure ◽  
Quaternary Structure ◽  
Normal Adult ◽  
Morphological Properties ◽  
Adult Males ◽  
Circular Dichroïsm ◽  
Urinary Glycoprotein

Much work has been reported on the chemical, physical and morphological properties of urinary Tamm-Horsfall glycoprotein (THG). Although it was once reported that cystic fibrotic (CF) individuals had a defective THG, more recent data indicate that THG and CF-THG are similar if not identical.No studies on the conformational aspects have been reported on this glycoprotein using circular dichroism (CD). We examined the secondary structure of THG and derivatives under various conditions and have correlated these results with quaternary structure using electron microscopy.THG was prepared from normal adult males and CF-THG from a 16-year old CF female by the method of Tamm and Horsfall. CF female by the method of Tamm and Horsfall.

Virus-Like Particles in a Human Breast Cancer: Structural Similarity to Previously Reported Particles

1973 ◽  
Vol 31 ◽  
pp. 378-379
Author(s):  
G. Kasnic ◽  
S. E. Stewart ◽  
C. Urbanski
Keyword(s):  
Breast Cancer ◽  
Biological Activity ◽  
Human Breast Cancer ◽  
Osteogenic Sarcoma ◽  
Human Tumor ◽  
Structural Similarity ◽  
Cell Tumor ◽  
Human Breast ◽  
Human Tumor Cell ◽  
Type Particle

We have reported the maturation of an intracisternal A-type particle in murine plasma cell tumor cultures and three human tumor cell cultures (rhabdomyosarcoma, lung adenocarcinoma, and osteogenic sarcoma) after IUDR-DMSO activation. In all of these studies the A-type particle seems to develop into a form with an electron dense nucleoid, presumably mature, which is also intracisternal. A similar intracisternal A-type particle has been described in leukemic guinea pigs. Although no biological activity has yet been demonstrated for these particles, on morphologic grounds, and by the manner in which they develop within the cell, they may represent members of the same family of viruses.

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