Studies on chemical modification of cold agglutinin from the snail <i>Achatina fulica</i>

Sarkar, Manisha; Mitra, Debashis; Sen, A. K.

doi:10.1042/bj2460157

Cited by 4 publications

(2 citation statements)

References 16 publications

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“…Other modifications of mucin reported include thermal, pH, chemical, physical etc (Sarkar, et al, 1987;Viney, et al, 1993;Baranowski, 2006;Adikwu and Eraga, 2007). These modifications have been reported to affect mucin properties such as aggregation and gelation, stability, rheology, adhesiveness, crystallinity and viscosity (Bansil and Turner, 2006).…”

Section: Introductionmentioning

confidence: 99%

Investigation of the Effect of Alkali Modification of Mucin on Some Properties of Metronidazole Bioadhesive Tablets

Eraga¹,

Arhewoh²,

Okogbenin³

et al. 2015

Journal of Applied Sciences and Environmental Management

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ABSTRACT:The objective of this study was to investigate the effect of alkali treatment of mucin on the mucoadhesive properties and tablet parameters of metronidazole tablets. Mucin was extracted from the African giant snails (Archachatina maginata) by differential precipitation using acetone, air-dried and pulverized. Different portion of the mucin powder was treated with mineral bases (sodium and ammonium hydroxides) and organic base (pyridine) at high and low concentrations and at varied times of 1 and 12 h. Ten batches of metronidazole tablets (B1-B10) were prepared with the modified mucin by direct compression. Their granules and tablets were evaluated for flow properties and tablets parameters, respectively. Tablet mucoadhesion was determined using the mass flow rate method. All the batches of granules gave good flow characteristics with their angles of repose < 30°. The formulated tablets passed the weight variation test and had hardness values within the range of 3.2 to 5.0 kp and friability of 0.7 to 2.0 % while the content of active drug met official compendial requirements. Tablets of 1 M NaOH treated mucin for 1 h gave the best mucoadhesion values of 5.95 g/sec, followed by the 0.1 M NaOH 12 h treatment and 0.1 M NaOH 1 h treatment with 4.34 g/sec and 4.14 g/sec, respectively. These values were higher than those of the unmodified mucin tablets which gave 0.75 g/sec. Tablets of 0.1M pyridine treated mucin for 1 h gave the least mucoadhesion values of 0.51 g/sec. Tablets of mucin treatment using NaOH gave improved mucoadhesive properties compared to the unmodified mucin. Thus, NaOH modified mucin can be preferred in the formulation of some mucoadhesive dosage forms. © JASEM

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Section: Introductionmentioning

confidence: 99%

Investigation of the Effect of Alkali Modification of Mucin on Some Properties of Metronidazole Bioadhesive Tablets

Eraga¹,

Arhewoh²,

Okogbenin³

et al. 2015

Journal of Applied Sciences and Environmental Management

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“…The cold agglutinin was found to be a glycoprotein of native Mr 220000, it agglutinated rabbit and human umbilical-cord erythrocytes only at low temperatures (optimum 13°C) and N-acetyl-lactosamine was found to be a specific inhibitor (Sarkar et al, 1984;Mitra et al, 1987). The carbohydrate part of the glycoprotein was found to be important for cold agglutinating behaviour (Sarkar et al, 1987). The present paper describes the binding characteristics of the cold agglutinin to its specific sugar by fluorescence spectroscopy with 4-methylumbelliferyl fl-D-galactopyranoside (MeUmbGalp).…”

Section: Introductionmentioning

confidence: 99%

Physicochemical studies of binding of 4-methylumbelliferyl β-d-galactopyranoside to cold agglutinin

Mitra

Sarkar

1989

Biochemical Journal

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The fluorescence of 4-methylumbelliferyl beta-D-galactopyranoside (MeUmbGalp) was quenched in the presence of cold agglutinin, showing that there was binding between MeUmbGalp and cold agglutinin. That binding was saccharide-specific. By using this quenching phenomenon, the association constants (Ka) of the binding of cold agglutinin at different temperatures (10 degrees C and 15 degrees C) to MeUmbGalp and also the number of binding sites were calculated. The Ka values were found to be 2.63 x 10(3) M-1 at 10 degrees C and 1.58 x 10(3) M-1 at 15 degrees C. Though there is a change in Ka values, the number of binding sites was calculated to be six at both temperatures (10 degrees C and 15 degrees C). From the Ka values the thermodynamic parameters (free energy, enthalpy and entropy) of the binding were derived, and analysis of the data indicated that the binding is spontaneous, exothermic and hydrophobic in nature.

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Chemical modification studies on a blood group A-specific lectin, crotalarin (Crotalaria striata) and its effect on hemagglutinating activity

Sikdar

Chatterjee

1990

Mol Cell Biochem

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Crotalarin, the N-acetyl-D-galactosamine-binding blood group A-specific lectin from the seeds of Crotalaria striata was subjected to various chemical modifications in order to ascertain the amino acid residues responsible for its carbohydrate-binding property. Modification of lysine, cysteine and arginine residues did not affect the carbohydrate-binding activity of the lectin. However, modification of tyrosine residue and carboxy group of the acidic amino acids led to a complete loss of its activity, indicating the involvement of tyrosine and aspartic and glutamic acid in the saccharide-binding respectively. The hemagglutinating activity of the lectin was completely/almost completely lost by modification of tryptophan residues. The relative loss in hemagglutinating activity on modification of tryptophan residues indicate that one residue/molecule is required for the carbohydrate-binding activity of the lectin. Modification was not effective in the presence of D-galactose (0.2 M). A marked decrease in the fluorescence emission was found as the tryptophan residues of crotalarin were modified. The c.d. spectra showed the presence of an identical pattern of conformation in the native and modified lectins which confirms that the loss in activity was due to modification only. The effect of periodate oxidation on crotalarin showed loss of activity whereas action of enzymes retained most of the activity.

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Studies on chemical modification of cold agglutinin from the snail Achatina fulica

Cited by 4 publications

References 16 publications

Investigation of the Effect of Alkali Modification of Mucin on Some Properties of Metronidazole Bioadhesive Tablets

Investigation of the Effect of Alkali Modification of Mucin on Some Properties of Metronidazole Bioadhesive Tablets

Physicochemical studies of binding of 4-methylumbelliferyl β-d-galactopyranoside to cold agglutinin

Chemical modification studies on a blood group A-specific lectin, crotalarin (Crotalaria striata) and its effect on hemagglutinating activity

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