Protein structure and protein hydration

Lloyd, Dorothy Jordan; Phillips, Henry

doi:10.1039/tf9332900132

Cited by 22 publications

(8 citation statements)

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“…Jordan Lloyd and Phillips (1933) have described a number of methods by which water molecules might be coordinated to atoms on the side chains of a peptide. Some of their conclusions have been criticized by Pauli (1934).…”

Section: The Densities O F Protein Crystalsmentioning

confidence: 99%

The densities of protein crystals and the hydration of proteins

Adair¹,

Adair²

1936

Proc. R. Soc. Lond. B

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The apparent densities of proteins in aqueous solutions have been studied by a number of investigators, including Chick and Martin (1913), and, more recently, by Svedberg and his colleagues, but comparatively few observations of the densities of protein crystals have been published. Eyer (1932) gave the value 1·315 for insulin, Crowfoot (1935) 1·306; Adair and Adair (1934) found 1·296 for haemoglobin; Bernal and Crowfoot (1934) gave 1·28 for pepsin. The media used for the measurements on pepsin and insulin were not recorded. A method for measuring the densities of small crystals by means of observing their flotation in media of different densities was described by Retgers (1889). The present communication records a modification of his method adapted for the investigation of the density of crystalline and of denatured proteins. The first problem studied was the choice of suitable media. The mixtures of organic liquids which are generally used for density determinations of inorganic crystals are open to objections on the grounds that protein crystals cannot be freed from films of their mother liquor without grave risks of irreversible changes. In working with aqueous media this difficulty need not arise, but the media chosen must fulfil the somewhat exacting requirements of a high density with freedom from the capacity to denature or to dissolve the protein.

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Section: The Densities O F Protein Crystalsmentioning

confidence: 99%

The densities of protein crystals and the hydration of proteins

Adair¹,

Adair²

1936

Proc. R. Soc. Lond. B

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“…In support of this conclusion, Peirce (1929) long ago stated that the hydration of cotton cellulose involved the association of one water molecule per hexose unit as in a chemical compound plus additional molecules held by attractive forces like those in liquid water. Similarly, Llyod & Phillips (1933) pointed out that the interaction of water with proteins was through hydrogen bonds on the polar side chains of proteins and to a lesser extent on the backbone imido and carboxyl groups. Pauling (1945) on the other hand suggested that only the side chain polar groups of proteins could bind water and that the backbone imido and carboxyl groups did not bind water at all which is not supported in these discussions.…”

Section: Discussionmentioning

confidence: 99%

Bound water: its definition, estimation and characteristics

Caurie¹

2011

Int J of Food Sci Tech

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Parameters of Caurie's [International Journal of Food Science and Technology 40 (2005) 283] unimolecular adsorption equation have been used to calculate total bound water to equal the square of the primary water capacity or m 0 2 grams. Current freezing methods predict bound water up to nm 0 grams which leaves a fraction of the total bound water with limited freezing properties unaccounted for. From these studies three types of bound water have been identified at room temperature along a decreasing energy gradient. It has been shown that the stability of processed and blended foods will improve with formula modifications consistent with expansion of type II bound water molecules and processed foods will be more stable the smaller the fractional ratio of type III to type II bound water molecules.

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“…It is therefore probable that the isoelectric point of these molecules lies between these values. The influence of variation in pH upon the hydration of a system of this kind has been treated theoretically by Lloyd & Phillips (1933). Thus (p. 137) 'The molecules of an organized protein can approach as closely as the length of their side chains permits.…”

Section: Discussionmentioning

confidence: 99%

The mode of reaction of interstitial connective tissue with water

Day¹

1949

The Journal of Physiology

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When water was injected into the subcutaneous tissues of a freshly killed animal, it was observed to accumulate around the point of injection (Ranvier's 'Boule d'cedeme'). Other fluids, such as alcohol, did not localize in this way, but spread evenly and rapidly into the surrounding tissues. These facts suggested a peculiar avidity of the tissue for-water. Examination of the swollen tissue with the dark ground microscope showed separation, without visible alteration, of the collagen fibrils. For this reason, it was considered probable that the water had combined with a substance which lay between the fibrils rather than with the fibrils themselves (Day., 1948). A substance of this kind had been previously described (Day, 1947 a), and Flemming's observation (1876), that, in acid solutions of strength sufficient to cause the collagen fibres to swell, this substance became shrunken, was confirmed.The present investigation is concerned with those changes in the morphology of interstitial connective tissue which took place, in aqueous solutions, as the result of experimental variation of pH and of neutral salt concentration. The study was undertaken with the object of gaining further knowledge of the mode of reaction of this tissue with water with particular regard to the part played by the interfibrillary substance. METHODSThe material studied was the deep fascia immediately covering the ventral aspect of the thigh muscles of the rat. Pieces up to 1 cm. wide were removed from a freshly killed animal. Each was placed at once in at least 20 ml. of the fluid in which it was to be studied. The pH of the fluids was measured electrometrically, with a glass electrode apparatus, at the beginning and at the end of the period of immersion of the tissue. The pH of the fluids was varied by the addition of dilute HCI or NaOH. Where solutions of salts were concerned, the quantity of Na+ or Cl-so added, was so very small in comparison with the concentrations of the salt ions already present that they could be ignored. Usually, the tissue was left in the fluids overnight and at a room temperature between 18 and 200C.The changes which took place were observed with the naked eye and also microscopically using dark ground illuimination. A Leitz 'cardioid' type of condenser was employed in conjunction with a Pointolite illuminant.

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Protein structure and protein hydration

Cited by 22 publications

References 0 publications

The densities of protein crystals and the hydration of proteins

The densities of protein crystals and the hydration of proteins

Bound water: its definition, estimation and characteristics

The mode of reaction of interstitial connective tissue with water

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