Thermodynamic and hydrodynamic study of Bence-Jones proteins

Four Bence-Jones proteins were studied under physiological conditions (10 mM phosphate buffer solution (pH 7.0) and 100 mM NaCl) by the circular dichroism, fluorescence, and analytical centrifugation methods. Combined analysis of the optical melting curves for the proteins and their fragments demonstrated that the stability of VAD protein and its constant half was decreased as compared with the other Bence-Jones proteins. This was correlated with the ability of both the whole protein and its constant (but not variable) part to form amyloid fibrils. The data on the correlation of the decreased stability with an abnormal interaction of two constant C_L domains are reported.     

Immunochemical studies of serum, urine and calculus proteins in urolithiasis

Total serum protein levels in 70 patients with urolithiasis were not significantly different from those in 20 control subjects, although certain variations were detected in individual protein patterns. In contrast, total urinary protein was significantly higher in patients with urolithiasis. 4-6 different components, i.e., albumin, alpha 1-acidic glycoprotein, alpha 1-antitrypsin, Gc-globulin, fibrinogen and immunoglobulin G, were found in the matrices of calculi and in urine, suggesting that proteinuria may play a role in the formation of stones in patients with urolithiasis.     

The optical rotatory dispersion of Bence-Jones proteins

The optical rotatory dispersion of ten individual specimens of Bence-Jones proteins was studied. Although the specimens displayed a certain variation in their optical rotation, the dispersion constants of all of them were found to be very low, between 178 and 209 mμ. The constants increased upon denaturation to 215–223 mμ, which is the magnitude usually found for denatured proteins.     

Comparative studies on partial microsequence-analysis of Bence-Jones proteins

1. Sequence analyses of Bence-Jones proteins up to 15 amino acids from the N-terminus provide decision of subgroups. 2. Investigation of primary structure of 3 Bence-Jones proteins, monomer and dimer of a kappa type, is limited at position 9-10 using DABITC reagent, whereas DABITC/PITC double coupling method allows sequencing up to 20-21 amino acids. 3. Sequencing of tryptic peptides allows only determination of 6-9 amino acids. 4. Microsequencing of tryptic peptide T13a shows the allotypic variant, inv b+, of Bence-Jones proteins TRA and GAN.