An analysis of Bence-Jones protein

Abstract

BENcE-JONES protein, which is characterized by precipitation from solution at low temperatures (45-50') and resolution of the coagulum on boiling, is excreted in the urine in about 70 % of the cases of multiple myelomatosis.and occasionally also in allied diseases of the bone marrow and blood-forming organs. Of some seven hundred papers on myelomatosis which have appeared since Bence-Jones [1848] first noted the excretion of a peculiar substance in a case of 'mollities ossium', relatively few have dealt in detail with the chemistry of the protein. The purpose of the present communication is to give the results of an analysis of the amino-acid content of a sample of Bence-Jones protein obtained from a case of multiple myelomatosis which recently came under observation in the terminal stages, in the Tropical Ward of the Royal Infirmary, Liverpool; other features of the case will be-discussed elsewhere. The urine, which was collected daily under toluene for about 3 weeks immediately before the death of the patient, showed the typical reactions of ience-Jones protein and was free from normal plasma proteins. After storage at 00 the different samples were filtered and mixed;, part was reserved for isolation of the protein in soluble form, and the rest was coagulated for analysis. EXPERIMENTAL As the amount of material for amino-acid analysis was small, attention was confined to colorimetric and small scale isolation methods. No attempt was made to apply the general solubility method devised by Bergmann & Stein [1939]. All the colorimetric analyses were carried out by means of a Hilger 'Spekker' Absorptiometer. In using this instrument the drum reading obtained by comparing the coloured solution with the appropriate blank is referred to a calibration curve similarly prepared from standard solutions of the pure constituent being estimated. The light filter is so chosen as to give maximum sVnsitivity. Solutions for the 1 cm. cups should be made up to 10 ml. All the reagents used were of A.R. quality or were purified by standard procedures and were freshly made up in solution. 'Blank tests were carried out where necessary and all the procedures were submitted to preliminary test against standard protein preparations. Unless otherwise stated, the results obtained with Bence-Jones protein are the mean of two or more determinations and refer to the moisture-and ash-free material. Preparation of Bence-Jones protein. The pH of the urine was adjusted with acetic acid to the point of maximum precipitation in the cold and the coagulation completed by heating to 60°for 30 min. Exhaustive washing of the protein by centrifuging was carried out by allowing it to stand 1-2 days in the wash liquor and repeating this several times afresh-first with very dilute acetic acid, then Research Fellow, Medical Research Council. (433) water, water at 600, aqueous alcohol, absolute alcohol, and finally light petroleum twice overnight.' The latter was repeated by extracting twice for a day in a Soxhlet apparatus and the protein was then air-dried ...

Bence-Jones Proteinemia in Multiple Myeloma 1

“…A major difficulty in the way of this objective lies in the multiplicity of Bence-Jones proteins (18,19,22,27,28) and in their correspondingly varied properties, as illustrated by the differences in solubility, electrophoretic mobility, sedimentation rate, and serological properties observed in the urinary Bence-Jones proteins in our cases of myeloma (8, and the present study). These differences, reflected in the varied serum protein patterns of patients with Bence-Jones proteinemia, necessitate a broad and flexible analytical approach.…”

Multiple Myeloma. Iii. Effect of Urethane Therapy on Plasma Cell Growth, Abnormal Serum Protein Components and Bence Jones Proteinuria 1

“…When studied immunologically, specific precipitins of at least two antigenic types have been found (12,27,31). The amino acid composition has been reinvestigated recently by improved methods (32)(33)(34). Like gamma globulin, Bence Jones protein has a high hydroxyamino acid content, but an anomalous finding was the absence of the essential amino acid methionine (33).…”