Disposable microbore high-pressure liquid chromatography columns for protein and peptide separations.

A range of high-performance liquid chromatography (HPLC) columns with internal diameters of 0.25 to 1.8 mm have been constructed by securing glass or plastic tubing into standard HPLC fittings. These were packed with chromatographic materials chosen for operation at moderate pressures with high flow rates. These columns were shown to be effective in a conventional HPLC instrument for peptide and protein separations in reverse-phase mode and for proteins in ion-exchange and size-exclusion modes. The simple construction and low cost of these microbore columns allow them to be considered as disposable. Using only small amounts of any type of packing material, they have the flexibility to be adapted to a wide range of analytical and micropreparative separations.     

Selective analysis for adenosine using reversed-phase high-pressure liquid chromatography

A high-pressure liquid chromatographic procedure for the selective determination of adenosine in the presence of other nucleic acid components is reported. Reversed-phase microparticle columns and an isocratic elution mode of dilute potassium dihydrophosphate and anhydrous methanol were used. The analysis is specific for adenosine and is achieved in less than 10 min. An example of the use of this analysis in a biomedical study is reported.     

Analysis of leukotrienes by high-pressure liquid chromatography

A method is described for the partial synthesis of saturated mixed-chain phosphatidylcholines of a high degree (typically 99 mol%) of purity. This procedure has been designed to eliminate the contamination of the mixed-chain product by symmetric chain phosphatidylcholine and the mixed-chain isomer of the desired product, the two principal impurities introduced by previous techniques. This high degree of purity is obtained by employing a method designed for the complete enzymatic hydrolysis of the C-2 fatty acyl moiety in saturated symmetric phosphatidylcholines and a new technique for the acylation of lysophosphatidylcholines employing the catalyst 4-pyrrolidinopyridine. The versatility of this new procedure is illustrated with the synthesis of several saturated mixed-chain phosphatidylcholines.     

Rapid separation of acetylated oligosaccharides by reverse-phase high-pressure liquid chromatography.

Peracetylated saccharides were separated by chromatography on a reverse-phase support, eluting with mixtures of acetonitrile-water. Gradient elution for 2.5 h gave significant separations of all linear glucose oligomers containing up to 35 sugar residues. With isocratic elution retention was exponentially related to molecular mass and only slightly affected by linkage or anomeric configuration. The presence of glucosamine in various saccharides markedly reduced their retention.     

Analysis of metallonucleoside hydrolysis by high-pressure liquid chromatography

A number of ammine complexes of transition metals in the platinum group exhibit antitumor and mutagenic activities, which probably result from in vivo metal ion coordination to nucleic acids. Coordination at N-7 purine sites on nucleic acids may induce depurination through a general acid-catalyzed cleavage of the sugar-purine bond. This possibility was tested by observing the hydrolysis of [dGuo)(NH₃)₅Ru]³⁺ under physiological conditions. Since multiple products result from this reaction, a high-pressure liquid chromatography technique was developed for separating various ammineruthenium(III) complexes with purine, pyrimidine, and nucleoside ligands. Using this technique it was possible to identify and follow the relative concentrations of several of the hydrolysis products. These data were used to develop a preliminary reaction scheme for the decomposition of (dGuo)(NH₃)₅Ru(III). The net rate constant (1.8 × 10^?6 s^?1) for the disappearance of this complex yields an upper limit for the rate of metal-induced sugar hydrolysis. While the half-life ($\text{5}\text{days}\text{< t}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{< 28}\text{days}$) for the sugar hydrolysis reaction is substantially shorter than that for the free nucleoside under the same conditions, it cannot be concluded that this represents a major contribution to the mutagenicity of Ru(III) complexes.     

Purification of tyrosine hydroxylase by high-pressure liquid chromatography

Our study of tyrosine hydroxylase (tyrosine 3-monooxygenase, EC 1.14.16.2) from rabbit adrenals has identified two major requirements which are likely to be of general application for the optimal purification and recovery of enzyme activity consequent to high-pressure liquid chromatography: (i) recovery of activity is maximized by pretreatment of the high-pressure liquid chromatography column before each use with protein to saturate high affinity, nonspecific sites exposed by the methanol used for washing, and storage of the column. (ii) Both purification and recovery are critically dependent upon the molarity of the mobile phase buffer. Examination of high-pressure liquid chromatography purified rabbit adrenal tyrosine hydroxylase by nondenaturing gel electrophoresis indicated that tyrosine hydroxylase activity was associated with one of the two protein bands in the gel. Thus, the convenient purification procedure described in this report leads to preparative amounts of tyrosine hydroxylase which is approximately 50% homogeneous.     

Comparison of buffers and detection systems for high-pressure liquid chromatography of peptide mixtures.

Cell culture lines were established from the transplantable mouse hepatomas H6 and H129. Both cell lines had a doubling time about 30 h when maintained in medium containing 5% foetal bovine serum. H6 cells contained about 3-4 times more DNA-dependent RNA polymerase I (Pol I; ribonucleoside triphosphate--RNA nucleotidyltransferase, EC 2.7.7.6) than did H129 cells. Moreover, the H6-cell enzyme was more heat-labile than that from H129 cells. Steady-state contents of 28S rRNA were measured in both cell lines. Exponentially growing cultures of H6 cells contained about 6.5pg of 28S rRNA/cell, and similar cultures of H129 cells contained about 5.8pg/cell. Stationary cultures of both cell lines contained about 2pg of 28S rRNA/cell. By two different techniques, the half-time for turnover of 28S rRNA was estimated to be 16-17h for both H6 and H129 cells. Knowing the turnover rate and the steady-state concentration, one may calculate that both H6 and H129 cells synthesize 28S rRNA at a rate of about 0.25 pg/h per cell. The amount of template-bound Pol I activity was similar in nuclei isolated from H6 and H129 cell cultures. These data indicate that, although H6 cells contained 3-4 times more Pol I than did H129 cells, both cell lines synthesized rRNA at about the same rate.     

Determination of E. gracilis mRNA base composition using high-pressure liquid chromatography.

The purine and pyrimidine bases of E. gracilis have been separated using a high-pressure liquid chromatograph (HPLC). Each base was unambiguously identified by its characteristic elution profile and UV absorption spectrum. This method allows for the study of the base composition of mRNAs altered by pathological processes, exemplified here by the analysis and comparison of mRNAs from zinc sufficient and deficient organisms.     

The behaviour of peptides on reverse-phase supports during high-pressure liquid chromatography.

High-pressure ('performance') liquid chromatography has been used to investigate the reverse-phase chromatographic behaviour of peptides, ranging in length from 2 to 65 amino acid residues, which have originated from primary-sequence determinations or solution/solid-phase syntheses. By using a pyridine/formate-pyridine/acetate/propan-1-ol buffer system, as previously described [Hughes, Winterhalter & Wilson (1979) FEBS Lett. 108, 81-86], the influence of various experimental parameters were examined. (a) Peptide retention was observed to be temperature-independent between 25 and 55 degrees C. (b) The dependence of chromatographic retention on pH decreases with increasing peptide hydrophobicity. (c) Chromatographic results from C8- and C18-chain-length, as well as from 5 micrometers- and 10 micrometers-particle-size, supports were comparable. (d) The hydrophobic strength of the organic solvent in the mobile phase was observed to decrease: propan-1-ol approximately equal to propan-2-ol greater than acetonitrile much greater than methanol. (e) When gradient rates (% of buffer B/unit time) were systematically decreased, peptide retention decreased in a hyperbolic manner. Comparisons of the peptides chromatographed with respect to their measured retention properties and calculated hydrophobicities were performed by computer analysis. Deviation of peptide chromatographic behaviour was observed to be essentially independent of hydrophobicity, chain length and charge. On the basis of the measured retention properties of the chromatographed peptides, hydrophobic constants for the various amino acid side chains were determined and compared with similar constants available from the literature.     

Analysis of lectin properties with membrane ultrafiltration and high-pressure liquid chromatography.

A convenient method for the analysis of the binding properties of lectin with fluorogenic sugar chains is described. A lectin (concanavalin A or Datura stramonium agglutinin) was mixed with pyridylaminated sugar chains in buffer and the free chains obtained were isolated by membrane ultrafiltration. The amount of free sugar chains in the filtrate was measured by high-pressure liquid chromatography. The binding constants with the sugar chains, reaction kinetics, and other properties of these lectins were easily investigated. The method is simple and could be used to study the characteristics of any lectin in native form.     

Separation of the natural retinoids by high-pressure liquid chromatography

A reverse phase high-pressure liquid chromatography system for rapid separation of various retinoids (vitamin A and its analogs) with little or no degradation is described. This method permits detection of as little as 22 pmol of retinoic acid. The procedure has been applied to the study of retinoic acid metabolism in vitamin A-deficient hamsters.     

Analysis of derivatives of carbohydrates by high-pressure liquid chromatography

The behaviour of benzoylated derivatives of alditols, monosaccharides, disaccharides, amino sugars, and methyl glycosides in high-pressure liquid chromatography (h.p.l.c.) has been investigated. A system was devised, using the most basic equipment of a single pump and fixed-wavelength u.v. detector, which gave good separations of the components of mixtures of derivatised methyl glycosides. Fractionation of complex mixtures of many of the other benzoylated carbohydrates was achieved in less than 30 min. The 4-nitrobenzoates were less useful for routine analyses.     

Determination of plasma oxalic acid by high-pressure liquid chromatography

A new specific and sensitive method for determination of oxalic acid in plasma by High Performance Liquid Chromatography (HPLC) is described. The plasma sample is deproteinized by ultrafiltration. The oxalic acid in the ultrafiltrate is purified by precipitation with CaCl2, new dilution of calcium oxalate precipitate, oxalic acid extraction with diethyl-ether and total dryness of the sample. The losses of oxalic acid during this process are evaluated by the addition of oxalic acid (U-14C) before the precipitation step. The dried samples are redissolved in mobile phase (o-H3PO4, 0.05 M) and injected into a HPLC chromatograph, with reversed phase column (Lichrosorb RP-8, Merck). Oxalate peak is detected spectrophotometrically at 220 nm with a retention time of 3.20 minutes. The method shows a mean recovery value of 82.11, with an intra-run and between-run CV values of 2.54 and 6.95 respectively. The oxalic acid measured in plasma by this method is 291 +/- 89 micrograms/100 ml plasma ultrafiltrate, in 16 normal subjects.     

Determination of adenosine kinase activity by high-pressure liquid chromatography

High-pressure liquid chromatography (reverse-phase mode) was used to assay adenosine kinase in cell and tissue extracts. The method is optimized for a rapid and selective analysis using 6-methylthiopurine riboside as substrate, isocratic elution and detection at 300 nm. A complete separation of substrate and product is achieved in about 3 min with no interference by other UV-absorbing compounds; the limit of detection is 20 pmoles.     

Separation of phycobiliprotein subunits by reverse-phase high-pressure liquid chromatography

Baseline separation of subunits of diverse phycobiliproteins was achieved by a reverse-phase HPLC gradient method with a C4 large-pore column and a solvent system consisting of 0.1% trifluoroacetic acid (TFA) in water and 0.1% TFA in 2:1 (v/v) acetonitrile:isopropanol. The procedure was successfully applied to cyanobacterial allophycocyanin and C-phycocyanins, an unusual phycocyanin from a marine cyanobacterium, red algal B- and R-phycoerythrins, and a cryptomonad phycoerythrin. The subunit sizes in these proteins range from about 7.5 to 30 kDa. Sample recovery was in excess of 85% in all cases. On-line spectroscopic analysis with a multiple diode array detector allowed determination of the type and number of bilins carried by each subunit.