Monolithic columns in high-performance liquid chromatography.

It is a privilege to be able to contribute to this volume in which Professor Zervas’ friends, students, and colleagues have joined together to honor him and his remarkable contributions to peptide chemistry. Although I did not know him until after his days in the Bergmann Laboratory at the Rockefeller Institute, I can claim the distinction of now working in those very same rooms that they occupied back in the mid-1930s. Like all peptide chemists, I am greatly indebted to Professor Zervas, having depended so heavily on the carbobenzoxy group and on the various modified urethan protecting groups which have been direct extensions of the revolutionary advance that Bergmann and Zervas made.

Solid-phase peptide synthesis.

Separation efficiencies in hydrophilic interaction chromatography.

A modification of the Edman degradation is described whereby peptides are degraded sequentially on a solid support by a machine, the solid-phase peptide sequencer. Reagents are pumped through a column containing the resin-bound peptide, and the amino acid thiazolinones released after each degradative cycle are collected on a fraction collector for subsequent analysis. A complete cycle requires 2 h, and all operations are controlled automatically by a programmer. An improved peptide resin is described, to which peptides can be attached in yields ranging from about 70% for the 30 amino acid insulin B-chain to nearly 100% for smaller peptides. Of the 18 amino acids examined so far, glycine, alanine, phenylalanine, tyrosine, valine, leucine, isoleucine, proline, methionine, asparagine, glutamine, histidine, lysine, threonine, serine and cysteic acid are degraded normally; the phenylthiohydantion of threonine is partially dehydrated and that of serine is almost completely destroyed by trifluoroacetic acid, however. The phenylthiohydantion of glutamic acid is not detected, because it remains bound by its γ-carboxyl group to the resin. When aspartic acid is encountered in peptides, further degradation is completely blocked, presumably as a result of the β-carboxyl group having formed a cyclic imide. Using the sequencer and unpurified reagents, it was possible to degrade entirely a 0.24 μmole sample of the 21 amino acid insulin A-chain (oxidized) and to analyze the products within a 3-day period. Degradative yields averaged 94% per cycle. Similarly, 0.1 μmole of the insulin B-chain was degraded through 18 cycles before identification of the phenylthiohydantoins became ambiguous. The sequencer is simple in design and operation, and is inexpensive to construct. The scope and limitations of the method are discussed.

https://febs.onlinelibrary.wiley.com/doi/pdf/10.1111/j.1432-1033.1971.tb01366.x

Solid-phase Edman degradation. An automatic peptide sequencer.

Fast, comprehensive two-dimensional liquid chromatography.

Operating parameters and separation of nucleotides on pellicular ion exchangers investigated by liquid chromatographic system

Seymour R. Lipsky

Papers

Fast liquid chromatography - An investigation of operating parameters and the separation of nucleotides on pellicular ion exchangers.

Rapid analysis of ribonucleosides and bases at the picomole level using pellicular cation exchange resin in narrow bore columns.

Column Design in High Pressure Liquid Chromatography

Fused Silica Glass Capillary Columns for Gas Chromatographic Analyses

Peak capacity in chromatography