Frank W. Putnam

Immunoglobulin Structure: Partial Amino Acid Sequence of a Bence Jones Protein

Sequence analysis and ordering of the soluble tryptic peptides of one Bence Jones protein and comparison with partial sequence data for another have revealed many structural differences in the half of the molecule with the terminal amino group, but only one structural difference in the half of the molecule having the terminal carboxyl group. Somatic chromosomal rearrangements may effect such changes and account for variability in antibody structure.

The heat precipitation of Bence-Jones proteins. I. Optimum conditions.

Abstract The heat precipitation of Bence-Jones proteins has been studied with respect to the type of protein, protein concentration, temperature, and electrolyte concentration and composition. A set of conditions for heating was established which resulted in the heavy precipitation of a wide variety of Bence-Jones proteins but not of normal serum proteins. On this basis, a simplified heat test for the detection of Bence-Jones protein in urine is proposed.

GAMMA GLOBULIN ANTIGENIC TYPES DEFINED BY HEAVY CHAIN DETERMINANTS.

Two populations of immunologically distinguishable 7S gamma globulins in normal human serum and two corresponding antigenic types of myeloma 7S gamma globulins have been detected with rabbit antiserums to proteins associated with pathological conditions, the differences being related to the H-chains of 7S gamma globulin. No relationship exists with type I and type II antigenic classification, determined by L-chains. Human serums with various hereditary gamma globulin (Gm) specificities contain both types of 7S gamma globulin.

Polymerism, polymorphism, and impurities in Bence-Jones proteins

Abstract The heterogeneity exhibited by Bence-Jones proteins in starch gel electrophoresis was found to be due to contamination with other proteins of diverse origins and to the presence of polymeric and polymorphic forms of Bence-Jones proteins. Isolation of purified major components of four Bence-Jones proteins was achieved by ion-exchange chromatography and gel filtration. Minor components were isolated by these means and were found to account for the three types of heterogeneity described. The Characteristic of dissolution at high temperatures, long considered a specific property of Bence-Jones proteins, was found to be shared by other proteins when the temperature range was extended above 100°.

HEMOGLOBIN POLYMORPHISM: ITS RELATION TO SICKLING OF ERYTHROCYTES IN WHITE-TAILED DEER.

Hemoglobins with different electrophoretic mobilities are associated with bizarre shapes seen during ordinary light microscopy of erythrocytes from the white-tailed deer, Odocoileus virginianus; nonsickling is contingent upon a specific hemoglobin. Sickling in vitro, which isproduced to a maximum degree in the presence of oxygen and elevated pH, is not associated with hematological abnormalities or disease despite marked differences in physical characteristics of sickled and nonsickled cells.

Chemical Composition and Molecular Parameters of Purified Plasma Proteins

Publisher Summary This chapter discusses the delineation of the purified plasma proteins, and the chemical composition and molecular parameters of plasma proteins. As fluctuating components of a dynamic, circulating system, the plasma proteins have always defied characterization and purification by any single method. Plasma, as the greatest single source of proteins of widespread interest, has challenged the protein chemist and prompted the development of new fractionation schemes such as the cold-ethanol method, and physical chemical techniques such as boundary and zone electrophoresis. Some plasma proteins such as complement, properdin, erythropoietin, and the isohemagglutinins are best detected by a biological property and have yet to be isolated in reasonably pure and identifiable form. Others such as serum albumin, the α 1 -acid glycoprotein, and ceruloplasmin are crystallizable and rather sharply definable.

Abnormal human serum globulins. I. The nonidentity of macroglobulins

Abstract In order to investigate molecular relationships among the macroglobulins (high-molecular-weight globulins of pathological sera), a systematic comparison has been made of the ultracentrifugal behavior and electrophoretic properties of eight purified specimens. These proteins all exhibited multiple high molecular weight components, yet appeared electrophoretically homogeneous except in one case. Several macroglobulins studied over a wide pH range had different mobility curves and isoelectric points; some were insoluble in the cold and others differed in N-terminal amino acids. Disaggregation of the macroglobulins to form subunits of the size of normal γ-globulin but antigenically different could be accomplished with mercaptoethanol but not by change in temperature of pH, or by ultrasonic vibration or the addition of urea. The molecular interactions of macroglobulins and the physiological significance of the phenomenon are considered. It is concluded that the macroglobulins comprise a class of pathological serum proteins linked together by their ultracentrifugal behavior and certain antigenic determinants, but differing widely in other characteristics. Despite their manifold relationships to normal γ-globulin, macroglobulins appear to be abnormal proteins resulting from individually specific aberrations in serum protein synthesis.

Site of cleavage of γ-globulins by papain

Abstract Limited cleavage of γ-globulins of several species by a variety of proteolytic enzymes yields 3.5-S fragments apparently representing adjoining structural moieties of the parent molecules. The locus, specificity, and stoichiometry of the peptide bonds involved have been studied by N-terminal group assay. Sulfhydryl-activated plant proteases such as papain, bromelain, ficin, and chymopapain all cleave similar bonds in human γ-globulin and form similar 3.5-S fragments. The γ-globulins of different species vary in susceptibility to papain; rabbit γ-globulin and pathological human proteins are most readily cleaved. Ficin and papain yield indistinguishable fragments from rabbit γ-globulin, namely Fractions I and II, and Fraction III. The latter can be resolved into three subfractions, IIIA, B, and C. In general, the sensitive bond involves a branched-chain amino acid, usually leucine. However, a transient threonyl N-terminal group is liberated in early stages of the cleavage of normal γ-globulin later being replaced by leucine. Both peptide-bond rupture and disulfide-bond reduction are requisite for the formation of 3.5-S fragments, but the cleavage is apparently initiated by the proteolysis which exposes a critical disulfide bond. However, no structure common to the γ-globulins of the various species can yet be formulated because they differ in the nature and apparent number of N-terminal groups and do not yield the same number or types of 3.5-S fragments on cleavage by papain.

Immunoglobulin Structure: Amino- and Carboxyl-Terminal Peptides of Type I Bence Jones Proteins

Analysis of the amino acid sequence in Bence Jones proteins permits study of the structure of L-chains of normal immunoglobulins. An amino-terminal octadecapeptide containing the sole methionine residue occurs in many but not all immunoglobulins of antigenic type I. The carboxyl-terminal octapeptide appears invariant in type I proteins and ends in cysteine, which may have a cross-linking function.

The source of the apparent carbohydrate content of Bence-Jones proteins

Abstract Bence-Jones proteins prepared by repeated ammonium sulfate precipitation appear to contain variable amounts of carbohydrate. This has been shown to be due to contamination by other carbohydrate-containing substances. Fractions with high hexose contents were isolated from a Bence-Jones protein preparation, and similar materials appeared to be present in all the carbohydrate-containing proteins that were tested.