NOPR Collection:

Related affinities of different mono nucleotides and mono nucleotides towards Pr (III) and Nd (III) in aquated organic solvents explored through 4f-4f transition spectral analysis

2013-07-15T16:32:00Z

Title: Related affinities of different mono nucleotides and mono nucleotides towards Pr (III) and Nd (III) in aquated organic solvents explored through 4f-4f transition spectral analysis Authors: Misra, Sudhindra N; Suveerkumar, C M; Patel, Manish C; Bhatt, Prashant N; Mehta, Jignasu P Abstract: Spectroscopic properties of Pr (III ) and Nd (III)-mono nucleotides and nucleotides in aquated organic solvents have been investigated through absorption difference and comparative absorption spectroscopy involving 4f-4f transitions. Absorption intensity analysis, has shown that minor coordination changes in structure and chemical make-up of these structurally related ligands induced substantial changes in the intensities of 4f-4f bands and their perturbation has been reflected through oscillator strength , Judd-Ofelt intensity parameters (T_λ; λ = 2, 4, 6). The results show that different nucleosides and nucleotides bind Pr (III) / Nd (III) with different degrees of relative affinities. Page(s): 66-69

Solubilization of μ-opioid receptors enriched from bovine brain membranes

2013-07-24T16:31:27Z

Title: Solubilization of μ-opioid receptors enriched from bovine brain membranes Authors: Sastry, K V H; Yadgiri, B; Reddy, J M; Janardanasarma, M K Abstract: Solubilization is the most critical step in the purification of opioid receptors as these proteins are highly sensitive to detergents and get inactivated even with very mild detergents. Membranes enriched with μ-opioid receptors from bovine corpus striatum were solubilized by various methods to obtain the active soluble receptor suitable for affinity purification. Solubilization by digitonin resulted in marginal yields. CHAPS in presence of NaCl could extract active receptor into the solution. The detergent and NaCl were removed by either polyethylene glycol precipitation or by desalting on Sephadex G₅₀. The polyethylene glycol precipitation resulted in the formation of liposomes into which the receptor protein was incorporated. Liposome formation was not observed in desalting method and the recovery of the receptor was partial. Page(s): 60-65

Inactivation of maize NADP-malic enzyme by Cu²⁺ -ascorbate

2013-07-23T16:31:20Z

Title: Inactivation of maize NADP-malic enzyme by Cu²⁺ -ascorbate Authors: Pinto, S E; Rao, S R; Bhagwat, A S Abstract: Maize malic enzyme was rapidly inactivated by micromolar concentrations of cupric nitrate in the presence of ascorbate at pH, 5.0. Ascorbate or Cu²⁺ alone had no effect on enzyme activity. The substrate L-malate or NADP individually provided almost total protection against Cu²⁺-ascorbate inactivation. The loss of enzyme activity was accompanied by cleavage of the enzyme. The cleaved peptides showed molecular mass of 55 kDa, 48 kDa, 38 kDa, and 14 kDa. Addition of EDTA, histidine and imidazole provided protection. The results of protection experiments with sodium azide, DABCO and catalase suggested that reactive oxygen species were generated resulting in loss of enzyme activity. This was further supported by experiments showing that the rate of enzyme inactivation was higher in D₂O than in water. It is suggested that maize malic enzyme is modified by reactive oxygen species like singlet oxygen and H₂O₂ generated by Cu²⁺- ascorbate system and the modified amino acid residue(s) may be located at or near the substrate-binding site of the enzyme. Page(s): 55-59

Affinity purification and characterization of a seed lectin from Crotalaria medicaginea

2013-07-15T16:31:31Z

Title: Affinity purification and characterization of a seed lectin from Crotalaria medicaginea Authors: Kaur, Navjot; Singh, Jatinder; Kamboj, Sukhdev Singh Abstract: Purification of lectin from the seeds of Crotalaria medicaginea Lamk by affinity chromatography on asialofetuinlinked amino activated silica, yielded a single band on non-denatured PAGE at pH 4.5 and 8.3 and, a single peak on HPLC size exclusion and cation exchange columns. The molecular mass of the native C. medicaginea lectin was determined to be 125 kDa by gel filtration. In SDS-PAGE, the lectin migrated as a single band of M_r 31.6 kDa under reducing and nonreducing conditions, indicating that it is a tetramer of apparently identical subunits. It agglutinated red blood cells (RBCs) from rabbit and human ABO blood groups. It also reacted with RBCs from rat, sheep, goat and guinea pig but after desialylation with neuraminidase. The hemagglutination activity of the lectin was inhibited by D-galactose and its derivatives. Amino acid analysis showed that lectin was rich in aspartic and glutamic acid and, did not contain sulphur containing amino acids. The lectin is a glycoprotein having 1.41% of neutral sugars. It is labile at temperature above 60°C. It needs divalent cations for its activity, as a loss of activity was observed on removal of Ca²⁺ and Mn²⁺. Denaturing agents like urea, thiourea and guanidine-HCl have no effect on its activity. Page(s): 49-54

NOPR Collection:

Related affinities of different mono nucleotides and mono nucleotides towards Pr (III) and Nd (III) in aquated organic solvents explored through 4f-4f transition spectral analysis

Solubilization of μ-opioid receptors enriched from bovine brain membranes

Inactivation of maize NADP-malic enzyme by Cu2+ -ascorbate

Affinity purification and characterization of a seed lectin from Crotalaria medicaginea

Inactivation of maize NADP-malic enzyme by Cu²⁺ -ascorbate