Glucagon Structure and Function I. PURIFICATION AND PROPERTIES OF BOVINE GLUCAGON AND MONODESAMIDOGLUCAGON

摘要: Abstract Crystalline bovine or porcine glucagon was fractionated by chromatography on columns of DEAE-cellulose in the presence buffers containing 7 m urea. About 89% recovered protein comprises highly purified glucagon; 10% is monodesamidoglucagon and another 0.8% resembles amino acid composition electrophoretic mobility. The identified characterized largely means analysis, mobility, circular dichroic spectra, enzymatic degradations. Deamidation appears to occur randomly three glutamines positions 3, 20, 24, giving a mixture isomers. penultimate asparagine remained intact. Monodesamidoglucagon had less biological immunological activity than exhibited an altered spectrum; either covalent conformational changes, both, may be responsible for decrease activity.