Gerald Grübler

Capillary electrophoresis, a rapid and sensitive method for routine analysis of apolipoprotein A-I in clinical samples

A method for the determination of apolipoprotein A-I, the major protein compartment of HDL, in human serum is described. Rapid and easy serum sample preparation, well separated Apo A-I peaks in the human serum electropherogram and good linearity of the peak area vs. concentration plot, covering the range of the clinically relevant Apo A-I serum contents, suggest the introduction of this method routinely in clinical laboratories.

Capillary electrophoresis in biochemical and clinical laboratories: Selected attractive examples

As demonstrated by selected examples from our laboratories, CE is a unique methodology for purity control of synthetic as well as natural tissue-isolated biopolymers, a prerequisite before reliable biotestings should be performed. A combination of rapid matrix-assisted laser desorption ionization mass and CE electrophoretic mobility determinations facilitates primary sequence determinations of enzymatic peptide digest mixtures often making costly Edman degradations unnecessary. The enormous separation efficiency and large variety of different possible separation modes in CE, allow detection of single components in complex mixtures which is demonstrated by the apolipoprotein A-I determination in human blood serum in this communication.

Carboxamidomethyl ester as useful handle in polystyrene-based peptide synthesis: Cleavage of peptide with mercaptide

Abstract Glycolamidic ester linkage of a peptide chain to a polystyrene resin can be cleaved with the lithium salt of mercaptoethanol, allowing utilization of this handle for Boc strategy of solid phase peptide synthesis.

OPTIMIZED AUTOMATED SOLID PHASE SYNTHESIS OF OLIGONUCLEOTIDES AND DERIVATIVES

An optimized automated synthesizer is presented for assembling oligonucleotides, thiooligonucleotides and 5′-modified oligonucleotides including: chemical phosphorylation, multihydroxyl derivatization with a non-nucleosidic phosphoramidite. The incorporation of biotin, fluorescein and rhodamine phosphoramidites is described. The purification and structure determination of oligo-nucleotides was confirmed using high performance liquid chromatography (HPLC), capillary electrophoresis (CE) and laser desorption mass spectrometry (LDMS). Several applications and confirming data will be presented for gene synthesis and polymerase chain reaction (PCR) experiments.

A test-case for the 1-(1-adamantyl)-1-methylethoxycarbonyl (Adpoc) group: solid-phase synthesis of LH-RH using Na-Adpoc protection and an labile handle

Abstract A solid-phase synthesis of a sensitive decapeptide amide using N a -Adpoc protection and an acid-labile handle significantly widens the scope of this amino-protective group.

An HPLC system for use in the development of new arginine protecting groups

SummaryAn HPLC system with a highly specific post-column reaction detector for free guanidino groups has been developed. For use in the quantitative determination of the cleavage kinetics of side chain protecting groups of arginine. The detection system utilizes the specific fluorescent dye formation reaction of 9,10-phenanthrenequinone with the free guanidino groups in arginine and simultaneously detects UV-absorbing components in the eluent. The HPLC system allows optimization of the cleavage conditions for individual side chain protecting groups of arginine and gives invaluable information for use in choosing the optimal strategy for the syntheses of arginine-containing peptides.