Separation of interleukins by a preparative chromatofocusing-like method

Separation of protein charge variants with induced pH gradients using anion exchange chromatographic columns

“…One approach is to use strong exchangers with externally generated temporal pH gradients formed by mixing mobile phases containing nonretained buffering species prepared at high and low pH values. For example, separations of isoforms with pH gradients have been shown for deamidated variants of a mAb17 and of recombinant interleukin,18 for amino acid variants of β‐lactoglobulin,19 and for phosphorylated variants of ovalbumin 20. Much like salt gradients, externally generated temporal pH gradients are sometimes difficult to implement in large scale due to the mixing requirements.…”

Positional Isomers of Monopegylated Interferon α-2a: Isolation, Characterization, and Biological Activity

“…E-mail: YU-CHING.PAN@roche.com. modification of a previously published procedure used 2 Abbreviations used: IFN, interferon a-2a; MALDI-TOF-MS, ma-to separate deamidated from amidated human intrix-assisted laser desorption ionization time of flight-mass specterleukin-1 a and N-Met from des-Met human intertrometry; PEG, polyethylene glycol; PEG-IFN, IFN modified with a leukin-1 b (8). In addition, the results obtained from single molecule of PEG 5000; RP-HPLC, reversed-phase high-perforstructural analyses and bioactivity assays of these mance liquid chromatography; SP, sulfopropyl; TFA, trifluoroacetic acid; MDBK, Madin-Darby bovine kidney.…”

High‐Performance Liquid Chromatography of Biological Macromolecules

“…Chromatofocusing does not necessarily have to be carried out on anion exchangers. Monkarsh et al 634 used, for example, a preparative strong cation-exchange sulfopropyl silica column in a quasichromatofocusing set-up with a gradient of acetate/phosphate buffers at increasing pH to resolve two 154-amino-acid fragments of recombinant human interleukin-1a differing by deamidation of one Asn (pI 5.1 and 5.3, respectively). In this 75 mL min 1 eluent flow rate preparative separation, the use of inexpensive buffer components represents a significant saving over polybuffers.…”