Samuel Solomon

The isolation of peptides by high-performance liquid chromatography using predicted elution positions☆

Abstract This paper describes the derivation and use of predictive retention coefficients for the reversed-phase high-performance liquid chromatography of peptides. The use of predicted elution positions in the isolation of peptides is illustrated by two examples where peptides, whose existence was postulated from cDNA sequence data, have been successfully isolated. The combination of the powerful chromatographic technology and the ability to predict the elution positions of peptides based on their composition provides a very potent method for the isolation of peptides from biological tissues.

The Use of Perfluorinated Carboxylic Acids in the Reversed-Phase HPLC of Peptides

Abstract The relative effectiveness of trifluoroacetic acid (TFA), pentafluoropropanoic acid (PFPA), heptafluorobutyric acid (HFBA) and undecafluorocaproic acid (UFCA) as hydrophobic counter-ions in the reversedphase high performance liquid chromatography (RP-HPLC) of peptides was assessed. Four solvent systems were compared each containing 0.01M of a perfluorocarboxylic acid throughout. Twelve standard peptides and proteins were loaded onto the RP-HPLC column which was eluted with a linear gradient of 20-58.4% aqueous acetonitrile over 90 minutes. The retention times of the peptide standards were different in each solvent system. In progressing from TFA to PFPA, HFBA and UFCA all the peptides showed greater retention times. However, the effect was most marked with peptides having the greatest number of basic groups. By exploiting this behaviour a different type of chromatography can be introduced into the RP-HPLC purification of peptides. For instance, column fractions obtained from the use of the TFA so...

GRANULINS, A NOVEL CLASS OF PEPTIDE FROM LEUKOCYTES

We report the isolation and characterization of a novel class of leukocyte peptides with possible cytokine-like activities which we call granulins. They are cystine-rich with molecular weights of approximately 6 Kda, except for granulin D, which appears to be a dimer. We present the sequence of one member of this family, a 56 residue peptide, granulin A, and amino-terminal sequences for three other granulins from human peripheral leukocytes. A fifth related peptide was isolated and partially sequenced from rat bone marrow, suggesting that at least some of the granulin in peripheral leukocytes is preformed in the marrow. Rat granulin, and human granulin A, are closely related, showing that the granulin structures are highly conserved between species.

SECRETION RATE OF ALDOSTERONE IN NORMAL PREGNANCY

There is a progressive rise in excretion of the metabolites of the estrogens (1) and of progesterone 1 (2) during pregnancy in humans. In late pregnancy, these hormones are largely placental in origin (3-6). The physiological role of the adrenal gland in pregnancy is still not well understood. The high levels of blood hydrocortisone found in pregnancy were initially explained as a reflection of an increased secretion of adrenal cortical hormones (7). More recently, it has been shown that the high blood levels of hydrocortisone in pregnancy could be accounted for by the increased binding of this hormone to blood proteins (8). It has been reported that aldosterone is secreted in increased amounts during pregnancy (9, 10). From available evidence, it has been concluded that in humans aldosterone is not a secretory product of the placenta (11-14), but that it is formed in the adrenal gland. In earlier studies (15-17), bioassay of the crude urinary extract revealed little or no increase in the salt-retaining factor in pregnancy as compared with the normal nonpregnant state. Barnes and Quilligan (18) reported the same findings with a bioassay of urinary extracts purified by three paper chromatographic systems. In 1956, Venning and Dyrenfurth (19) bioassayed extracts

Structure of a novel human granulocyte peptide with anti-ACTH activity

We report the purification, structure and biological properties of a peptide of novel sequence from human granulocytes that inhibits ACTH stimulated synthesis of corticosterone in rat adrenal cell suspensions. The peptide HP-4 is homologous to a previously described human granulocyte peptide HP-1 that has no anti-ACTH activity.

Cortisol receptors in rabbit fetal lung

Abstract Rabbit fetal lung nuclei contain macromolecules which have the properties of physiological receptors for cortisol by the criteria of specificity of binding and saturation of binding sites at low concentrations of the hormone The number of nuclear receptor sites is relatively low at 20 days of gestation, reaches a maximum at about 28–30 days of gestation and drops slightly after birth. These results correlate well with previously reported changes in pulmonary epithelial cell maturation and surfactant concentrations in rabbit fetal lung extracts. Preliminary evidence for the presence of cytoplasmic cortisol-binding components in fetal lung cells is also presented.

POMC-derived peptides and their biological action.

ABSTRACT: It has long been known that a large number of POMC‐related peptides are found in skin. In this introduction I describe the formation of POMC‐derived peptides in various tissues to indicate that processing is largely tissue‐dependent. I focus on the peptides from the N‐terminal fragment, such as γ‐MSH, ACTH and α‐MSH, and β‐lipopropin as well as β‐endorphin. I touch on the factors that control the synthesis of the various peptides, which are now numerous and varied, and again are tissue specific. The biologic activity of the peptides generated from POMC are described in relation to their possible action in skin. In addition, I describe a new class of peptides induced in skin following injury and which are of great interest.

Rapid separation of the α,β,Gγ and Aγ human globin chains by reversed-phase high pressure liquid chromatography☆

Abstract The main human globin chains present in cord blood hemoglobins, α,β,Gγ and Aγ, can be separated in 45 minutes by reversedphase high pressure liquid chromatography. The chains were identified by carboxymethyl cellulose chromatography and partial amino acid analysis of the cyanogen bromide fragments of the two γ chains. The purification of cyanogen bromide fragments and the separation and quantitation of their dansylated amino acids were accomplished using a similar system to that used for the separation of the globin chains. These results show the potential of this type of chromatography for the analytical and semi-preparative analysis of globin chains and the large advantages over conventional chromatographic techniques.

The isolation and characterization of γ3-melanotropin from the neurointermediary lobe of the rat pituitary

Summary γ 3 -Melanotropin has been isolated from the neurointermediary lobe of the rat pituitary by reversed-phase high performance liquid chromatography. Peptide mapping and amino acid analysis have demonstrated that γ 3 -melanotropin is a glycopeptide of 25 amino acids, which corresponds exactly to the γ 3 -melanotropin sequence predicted by DNA sequencing, with the addition of an extra lysine residue at the amino terminus. The carbohydrate chain is linked to the peptide between asparagine 16 and the carboxyl terminal glutamine 25, and contains 4 moles of glucosamine per mole of peptide but no galactosamine.

The levels and biologic action of the human neutrophil granule peptide HP-1 in lung tumors

HP-1 is the most abundant human representative of a recently discovered class of neutrophil cystine- and arginine-rich peptides. These peptides have many potentially regulatory activities expressed at nanomolar concentrations. To establish the levels of HP-1 that can accumulate in human lung tumors and nondiseased lung fragments, tissues were extracted for their peptide content. The extracts were purified on reverse phase HPLC, and HP-1 and related peptides were identified by sequence analysis and their concentrations in the tissue quantitated by amino acid analysis. Immunohistochemistry was performed and strongly suggests that HP-1 is confined to granulocytes under most circumstances, and indicates that the levels of HP-1 measured in the tumors reflect the levels obtained when solid tissue is infiltrated by neutrophils. The maximum observed levels were 26 nanomoles per gram wet weight of tissue. Attempts were then made to correlate this level to the cytotoxic potential of HP-1 by performing in vitro cytotoxicity dose-response curves on several cell lines. Most cells were killed at between 1 and 8 microM, and the response depended on the growth conditions of the cells. The levels of HP-1 that accumulate in tumors can exceed the in vitro cytolytic concentrations. The levels are also considerably in excess of those required to exert in vitro regulatory actions.