Single-step method of RNA isolation by acid guanidinium thiocyanate-phenol-chloroform extraction

https://www.biosyn.com/Images/ArticleImages/pdf/A%20simple.pdf

A simple method for displaying the hydropathic character of a protein

After infection and a prolonged incubation period, the scrapie agent causes a degenerative disease of the central nervous system in sheep and goats. Six lines of evidence including sensitivity to proteases demonstrate that this agent contains a protein that is required for infectivity. Although the scrapie agent is irreversibly inactivated by alkali, five procedures with more specificity for modifying nucleic acids failed to cause inactivation. The agent shows heterogeneity with respect to size, apparently a result of its hydrophobicity; the smallest form may have a molecular weight of 50,000 or less. Because the novel properties of the scrapie agent distinguish it from viruses, plasmids, and viroids, a new term "prion" is proposed to denote a small proteinaceous infectious particle which is resistant to inactivation by most procedures that modify nucleic acids. Knowledge of the scrapie agent structure may have significance for understanding the causes of several degenerative diseases.

http://science.sciencemag.org/content/sci/216/4542/136.full.pdf

Novel proteinaceous infectious particles cause scrapie

Analysis of the accuracy and implications of simple methods for predicting the secondary structure of globular proteins.

A method is presented for locating protein antigenic determinants by analyzing amino acid sequences in order to find the point of greatest local hydrophilicity. This is accomplished by assigning each amino acid a numerical value (hydrophilicity value) and then repetitively averaging these values along the peptide chain. The point of highest local average hydrophilicity is invariably located in, or immediately adjacent to, an antigenic determinant. It was found that the prediction success rate depended on averaging group length, with hexapeptide averages yielding optimal results. The method was developed using 12 proteins for which extensive immunochemical analysis has been carried out and subsequently was used to predict antigenic determinants for the following proteins: hepatitis B surface antigen, influenza hemagglutinins, fowl plague virus hemagglutinin, human histocompatibility antigen HLA-B7, human interferons, Escherichia coli and cholera enterotoxins, ragweed allergens Ra3 and Ra5, and streptococcal M protein. The hepatitis B surface antigen sequence was synthesized by chemical means and was shown to have antigenic activity by radioimmunoassay.

https://www.pnas.org/content/pnas/78/6/3824.full.pdf

Prediction of protein antigenic determinants from amino acid sequences.

http://staff.ustc.edu.cn/~liuyz/methods/AA_solubility.pdf

The Solubility of Amino Acids and Two Glycine Peptides in Aqueous Ethanol and Dioxane Solutions ESTABLISHMENT OF A HYDROPHOBICITY SCALE

Removal of detergent from mixed micelles of egg yolk phosphatidylcholine and octyl glucoside leads to formation of unilamellar phospholipid vesicles with a diameter of about 230 nm. The same procedure applied to mixed micelles containing the transmembrane protein glycophorin A, in addition to lipid and detergent, produces vesicles of the same size with glycophorin incorporated into the bilayer. The pure lipid vesicles are highly impermeable to both anions and cations, and incorporation of up to 220 molecules of glycophorin per vesicle has little effect on permeability.

Phospholipid vesicle formation and transmembrane protein incorporation using octyl glucoside

The solubility of amino acids and related compounds in aqueous urea solutions.

Publisher Summary This chapter describes the criteria of purity of guanidine hydrochloride (GuHCl) samples and the methods of producing pure samples, based on a laboratory manual GuHCl has proved to be the most powerful among commonly used protein denaturants and is being used for a variety of purposes There are two methods for obtaining a GuHCl sample of good quality: the recrystallization of commercial preparation and the conversion of guanidinium carbonate into chloride Before deciding the method that should be adopted, it must be noted that the purity requirement depends on the type of experiment In many cases, a sample of the highest quality adhering to solubility, melting point, and absorption spectrum requirements is not needed, and such a sample may be prohibitively expensive, for example, for gel chromatography for the determination of the molecular weight of proteins

The preparation of guanidine hydrochloride.

http://www.jbc.org/content/245/7/1648.full.pdf

Yasuhiko Nozaki

Papers

The Solubility of Amino Acids and Two Glycine Peptides in Aqueous Ethanol and Dioxane Solutions ESTABLISHMENT OF A HYDROPHOBICITY SCALE

Phospholipid vesicle formation and transmembrane protein incorporation using octyl glucoside

The solubility of amino acids and related compounds in aqueous urea solutions.

The preparation of guanidine hydrochloride.

The solubility of amino acids, diglycine, and triglycine in aqueous guanidine hydrochloride solutions.