The use of circular dichroism active phospholipid to study bacteriorhodopsin-lipid interaction. Effects of lipid to protein ratio and crosslinkings of lysine residues

1. Erabutoxins, a, b and c, neurotoxic proteins of a sea snake Lacticauda semifasciata, were guanidinated with O-methylisourea. The amino groups of all the lysine residues and those at the N-termini of the toxins were modified. The lethal activity of the toxins decreased to 50% (erabutoxins a and b) or 17% (erabutoxin c) of the original value on the modification. The c.d. (circular dichroism) maximum at 227 nm of the modified toxins became lower, whereas the whole profile of the c.d. curve remained unchanged. 2. The amino groups of erabutoxin b were acetylated with acetic anhydride. All the five monoacetyl derivatives were isolated from the reaction products by CM-cellulose and Bio-Rex 70 column chromatography. [1-Nalpha-acetylarginine]-, [15-N6-acetyl-lysine]- and [51-N6-acetyl-lysine]-erabutoxin b retained the toxicity of the native toxin, whereas [27-N6-acetyl-lysine] and [47-N6-acetyl-lysine]-erabutoxin b were 17 and 8% active respectively. The overall profile of c.d. spectrum of erabutoxin b remained unchanged on the monoacetylation.

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Discriminating between dispersion and lyoprotection effects in biocatalysis in organic media

Canadian Journal of Chemistry ◽

10.1139/v02-026 ◽

2002 ◽

Vol 80 (6) ◽

pp. 551-554 ◽

Cited By ~ 2

Author(s):

Francesco Secundo ◽

Giacomo Carrea ◽

Francesco Maria Veronese

Keyword(s):

Circular Dichroism ◽

Ethylene Glycol ◽

Candida Antarctica ◽

Pseudomonas Cepacia ◽

Organic Media ◽

Candida Antarctica Lipase ◽

Lipase B ◽

Protein Ratio ◽

Activation Effect ◽

Circular Dichroïsm

The increment of activity and solubility in 1,4-dioxane of lipase B from Candida antarctica, lipase from Pseudomonas cepacia, and subtilisin, were investigated as a function of the methoxypoly(ethylene glycol)protein (PEGprotein) ratio employed during lyophilization. Both activity and solubility markedly increased as the PEGprotein ratio was increased. The increment of activity at low PEGprotein ratios, however, was much higher than that of solubility. These data suggest that the PEG-induced activation effect is due mainly to a lyoprotection effect rather than to relaxation of diffusional limitations.Key words: hydrolases, activity, dispersion, lyoprotection, circular dichroism.

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The influence of lysolecithin on the complex formation between β-lactoglobulin and κ-casein

Journal of Dairy Research ◽

10.1017/s0022029900014850 ◽

1974 ◽

Vol 41 (1) ◽

pp. 9-17 ◽

Cited By ~ 16

Author(s):

O. Korver ◽

H. Meder

Keyword(s):

Circular Dichroism ◽

Complex Formation ◽

Spectral Measurements ◽

Native Conformation ◽

Protein Ratio ◽

Β Lactoglobulin ◽

Circular Dichroism Data ◽

Circular Dichroïsm

SummaryUltraviolet difference spectral measurements and some circular dichroism data are reported on the systems (β-lactoglobulin (BLG)/soya-lysolecithin (sll)), (κ-casein (KC)/sll) and (BLG/KC/sll). Sll destabilizes the native conformation of BLG and KC and promotes the interaction between BLG and KC. The influence of sll: protein ratio and time of heating on the complex formation has been investigated.

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Circular dichroism active artificial phospholipids for the study of molecular membrane dynamics focused on lipid—lipid interaction

Tetrahedron Letters ◽

10.1016/s0040-4039(00)85011-x ◽

1986 ◽

Vol 27 (38) ◽

pp. 4589-4592 ◽

Cited By ~ 5

Author(s):

Iwao Tabushi ◽

Takako Nishiya

Keyword(s):

Circular Dichroism ◽

Membrane Dynamics ◽

Circular Dichroïsm ◽

Lipid Interaction

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Characterization of Tamm-Horsfall Urinary Glycoprotein

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010007254x ◽

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.

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