scholarly journals Isolation and partial characterization of a D-galactose-binding lectin from the latex of Synadenium carinatum

2005 ◽  
Vol 48 (5) ◽  
pp. 705-716 ◽  
Author(s):  
Maria Aparecida Souza ◽  
Francielle Amâncio-Pereira ◽  
Cristina Ribeiro Barros Cardoso ◽  
Adriano Gomes da Silva ◽  
Edmar Gomes Silva ◽  
...  

A lectin from the latex of Synadenium carinatum was purified by affinity chromatography on immobilized-D-galactose-agarose and shown to be a potent agglutinin of human erythrocytes. The haemagglutination of human red cells was inhibited by 3.0 mM N-acetyl-D-galactopyranoside, 6.3 mM methyl-beta-D-galactopyranoside, 50 mM methyl-alpha-D-galactopyranoside and 50 mM D-fucose but not by L-fucose, demonstrating an anomeric and a conformational specificity. According to SDS-PAGE analysis, the lectin appeared to be a glycoprotein composed of two polypeptide chains of ca. 28 and 30 kDa, but size exclusion chromatography (Sephadex G-100) and native PAGE revealed a protein of apparent molecular weight 120 - 130 kDa made up of 28 and 30 kDa subunits. The lectin was stable in the range pH 6 - 9, and 4 - 56ºC. The N-terminal sequence of the 30 kDa subunit contained the conserved consensus sequence GPN observed in other D-galactose-binding lectins found in latex of members of the Euphorbiaceae.

1990 ◽  
Vol 272 (3) ◽  
pp. 721-726 ◽  
Author(s):  
V L Koshte ◽  
W van Dijk ◽  
M E van der Stelt ◽  
R C Aalberse

A lectin (BanLec-I) from banana (Musa paradisiac) with a binding specificity for oligomannosidic glycans of size classes higher than (Man)6GlcNAc was isolated and purified by affinity chromatography on a Sephadex G-75 column. It did not agglutinate untreated human or sheep erythrocytes, but it did agglutinate rabbit erythrocytes. BanLec-I stimulated T-cell proliferation. On size-exclusion chromatography, BanLec-I has a molecular mass of approx. 27 kDa, and on SDS/PAGE the molecular mass is approx. 13 kDa. The isoelectric point is 7.2-7.5. BanLec-I was found to be very effective as a probe in detecting glycoproteins, e.g. on nitrocellulose blots.


2002 ◽  
Vol 367 (1) ◽  
pp. 49-56 ◽  
Author(s):  
Dipali SINHA ◽  
Mariola MARCINKIEWICZ ◽  
David GAILANI ◽  
Peter N. WALSH

Human factor XI, a plasma glycoprotein required for normal haemostasis, is a homodimer (160kDa) formed by a single interchain disulphide bond linking the Cys-321 of each Apple 4 domain. Bovine, porcine and murine factor XI are also disulphide-linked homodimers. Rabbit factor XI, however, is an 80kDa polypeptide on non-reducing SDS/PAGE, suggesting that rabbit factor XI exists and functions physiologically either as a monomer, as does prekallikrein, a structural homologue to factor XI, or as a non-covalent homodimer. We have investigated the structure and function of rabbit factor XI to gain insight into the relation between homodimeric structure and factor XI function. Characterization of the cDNA sequence of rabbit factor XI and its amino acid translation revealed that in the rabbit protein a His residue replaces the Cys-321 that forms the interchain disulphide linkage in human factor XI, explaining why rabbit factor XI is a monomer in non-reducing SDS/PAGE. On size-exclusion chromatography, however, purified plasma rabbit factor XI, like the human protein and unlike prekallikrein, eluted as a dimer, demonstrating that rabbit factor XI circulates as a non-covalent dimer. In functional assays rabbit factor XI and human factor XI behaved similarly. Both monomeric and dimeric factor XI were detected in extracts of cells expressing rabbit factor XI. We conclude that the failure of rabbit factor XI to form a covalent homodimer due to the replacement of Cys-321 with His does not impair its functional activity because it exists in plasma as a non-covalent homodimer and homodimerization is an intracellular process.


Microbiology ◽  
2003 ◽  
Vol 149 (9) ◽  
pp. 2455-2462 ◽  
Author(s):  
Masaru Nagai ◽  
Maki Kawata ◽  
Hisayuki Watanabe ◽  
Machiko Ogawa ◽  
Kumiko Saito ◽  
...  

A laccase (EC 1.10.3.2) was isolated from the fully browned gills of Lentinula edodes fruit bodies. The enzyme was purified to a homogeneous preparation using hydrophobic, cation-exchange and size-exclusion chromatography. SDS-PAGE analysis showed the purified laccase, Lcc 2, to be a monomeric protein of 58·0 kDa. The enzyme had an isoelectric point of around pH 6·9. The optimum pH for enzyme activity was around 3·0 against 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)diammonium salt (ABTS), and it was most active at 40 °C and stable up to 50 °C. The enzyme contained 8·6 % carbohydrate and some copper atoms. The enzyme oxidized ABTS, p-phenylenediamine, pyrogallol, guaiacol, 2,6-dimethoxyphenol, catechol and ferulic acid, but not veratryl alcohol and tyrosine. β-(3,4-Dihydroxyphenyl)alanine (l-DOPA), which was not oxidized by a laccase previously reported from the culture filtrate of L. edodes, was also oxidized by Lcc 2, and the oxidative product of l-dopa was identified as l-DOPA quinone by HPLC analysis. Lcc 2 was able to oxidize phenolic compounds extracted from fresh gills to brown-coloured products, suggesting a role for laccase in melanin synthesis in this strain.


2020 ◽  
Author(s):  
Chihiro Inoue ◽  
Yoshitaka Abe ◽  
Nobutaka Fujieda

<p>Recently, the functional expression of group-5 hydroxylase component (MimA and MimC) in <i>Escherichia coli </i>along with its related chaperonin-like component (MimG) was reported by Furuya and Kino. In this study, we report the purification via a heterologous expression system and the biochemical characterization of MimAC, the complex of MimA and MimC and MimG to understand their exact roles. MimAC and MimG were fused with His-tags and purified using affinity chromatography in a homogenous state on SDS-PAGE. Blue native PAGE demonstrated that the quaternary structure of MimG was almost identical to that of chaperonin GroEL, indicating that its function was also similar to GroEL. Size-exclusion chromatography and ICP-AES analysis demonstrated that MimAC was assembled in the dimer of two sort of subunits and exhibited two iron atoms and at least one zinc atom per two subunits. This result indicated that MimAC possessed a dinuclear iron center, similar to other soluble diiron monooxygenase hydroxylases.</p>


2020 ◽  
Author(s):  
Chihiro Inoue ◽  
Yoshitaka Abe ◽  
Nobutaka Fujieda

<p>Recently, the functional expression of group-5 hydroxylase component (MimA and MimC) in <i>Escherichia coli </i>along with its related chaperonin-like component (MimG) was reported by Furuya and Kino. In this study, we report the purification via a heterologous expression system and the biochemical characterization of MimAC, the complex of MimA and MimC and MimG to understand their exact roles. MimAC and MimG were fused with His-tags and purified using affinity chromatography in a homogenous state on SDS-PAGE. Blue native PAGE demonstrated that the quaternary structure of MimG was almost identical to that of chaperonin GroEL, indicating that its function was also similar to GroEL. Size-exclusion chromatography and ICP-AES analysis demonstrated that MimAC was assembled in the dimer of two sort of subunits and exhibited two iron atoms and at least one zinc atom per two subunits. This result indicated that MimAC possessed a dinuclear iron center, similar to other soluble diiron monooxygenase hydroxylases.</p>


Molecules ◽  
2019 ◽  
Vol 24 (7) ◽  
pp. 1210 ◽  
Author(s):  
Lei Yu ◽  
Yonghong Li ◽  
Lei Tao ◽  
Chuncui Jia ◽  
Wenrong Yao ◽  
...  

During the past two decades, recombinant human interleukin-12 (rhIL-12) has emerged as one of the most potent cytokines in mediating antitumor activity in a variety of preclinical models and clinical studies. Purity is a critical quality attribute (CQA) in the quality control system of rhIL-12. In our study, rhIL-12 bulks from manufacturer B showed a different pattern in non-reduced SDS-PAGE compared with size-exclusion chromatography (SEC)-HPLC. A small fragment was only detected in non-reduced SDS-PAGE but not in SEC-HPLC. The results of UPLC/MS and N-terminal sequencing confirmed that the small fragment was a 261–306 amino acid sequence of a p40 subunit of IL-12. The cleavage occurs between Lys260 and Arg261, a basic rich region. With the presence of 0.2% SDS, the small fragment appeared in both native PAGE and in SEC-HPLC, suggesting that it is bound to the remaining part of the IL-12 non-covalently, and is dissociated in a denatured environment. The results of a bioassay showed that the fractured rhIL-12 proteins had deficient biological activity. These findings provide an important reference for the quality control of the production process and the final products of rhIL-12.


PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0244157
Author(s):  
Stephanie Menikou ◽  
Andrew J. McArdle ◽  
Ming-Shi Li ◽  
Myrsini Kaforou ◽  
Paul R. Langford ◽  
...  

A novel approach to recover and identify immune complexes (ICs) was developed using size exclusion chromatography (SEC) and affinity chromatography on immunoglobulin binding columns (HiTrap Protein G). The purification process was monitored by 1D SDS-PAGE, protein staining, Western blotting and, finally, liquid chromatography tandem mass spectrometry (LC MS/MS) was used to identify the recovered antigens. This approach was applied to serum with artificially created immune complexes (ICs) comprising vaccine antigen (influenza) and antibody, which led to recovery and identification of influenza peptides within the recovered ICs. This approach was compared with the established method for IC detection and recovery, polyethylene glycol (PEG) precipitation, followed by LC MS/MS. Both approaches successfully enabled capture, recovery and characterization of immunoglobulins and influenza antigen(s) in complex with the immunoglobulins. However, PEG precipitation has the advantage of simplicity and is more suited for large scale studies.


Toxins ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 582
Author(s):  
Cristian Franco-Servín ◽  
Edgar Neri-Castro ◽  
Melisa Bénard-Valle ◽  
Alejandro Alagón ◽  
Ramsés Alejandro Rosales-García ◽  
...  

The Baja California Peninsula has over 250 islands and islets with many endemic species. Among them, rattlesnakes are the most numerous but also one of the least studied groups. The study of island rattlesnake venom could guide us to a better understanding of evolutionary processes and the description of novel toxins. Crotalus helleri caliginis venom samples were analyzed to determine possible ontogenetic variation with SDS-PAGE in one and two dimensions and with RP-HPLC. Western Blot, ELISA, and amino-terminal sequencing were used to determine the main components of the venom. The biological and biochemical activities demonstrate the similarity of C. helleri caliginis venom to the continental species C. helleri helleri, with both having low proteolytic and phospholipase A2 (PLA2) activity but differing due to the absence of neurotoxin (crotoxin-like) in the insular species. The main components of the snake venom were metalloproteases, serine proteases, and crotamine, which was the most abundant toxin group (30–35% of full venom). The crotamine was isolated using size-exclusion chromatography where its functional effects were tested on mouse phrenic nerve–hemidiaphragm preparations in which a significant reduction in muscle twitch contractions were observed. The two Mexican antivenoms could neutralize the lethality of C. helleri caliginis venom but not the crotamine effects.


Holzforschung ◽  
2013 ◽  
Vol 67 (2) ◽  
pp. 123-128
Author(s):  
Andréia S. Magaton ◽  
Teresa Cristina F. Silva ◽  
Jorge Luiz Colodette ◽  
Dorila Piló-Veloso ◽  
Flaviana Reis Milagres ◽  
...  

Abstract 4-O-methylglucuronoxylans isolated from Eucalyptus grandis and Eucalyptus urophylla kraft black liquors (KBLs) were chemically characterized by Fourier transform infrared spectroscopy (FT-IR), size exclusion chromatography (SEC), and nuclear magnetic resonance (NMR) spectroscopy. Doses of alkali charge, expressed as active alkali (AA), were 16, 17, and 18% while the sulfidity was kept at 25%. Kappa numbers of 19.1, 17.5, and 16.1 for E. grandis and 20.4, 16.8, and 15.4 for E. urophylla were obtained. At higher alkali charges, the recovery of xylans from the KBLs was lower and the degree of substitution of xylans with uronic acids decreased. The average molecular weight (Mw) of the recovered xylans was greater under conditions of mild pulping, i.e., in the case of pulps with higher kappa numbers. Mw of xylans ranged from 16.1 to 19.1 kDa for E. grandis and from 15.4 to 20.4 kDa for E. urophylla. The xylans from KBL may be useful as pulp modifying agents or as a raw material for advanced applications.


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