Portal de Periódicos da CAPES

Presence of the ϵ-(γ-glutamic)lysine crosslink in cellular proteins

1979; Elsevier BV; Volume: 576; Issue: 2 Linguagem: Inglês

10.1016/0005-2795(79)90401-x

1878-1454

Slavica S. Matacic, Ariel G. Loewy,

Fungal Biology and Applications

The ϵ-(γ-glutamic)lysine bond is a covalent interaction which has been found to crosslink polypeptide chains of a number of extracellular proteins. Among known covalent bonds crosslinking protein chains, it is unique in that it is formed directly by enzymatic catalysis, a property which may also endow Glu-Lys crosslink formation with important intracellular functions. We found glutamic-lysine bonds to be present in the procaryote, Escherichia coli, in primitive eucaryotes such as the slime mold, Physarum polycephalum, and the ciliate, Paramecium aurelia, and in muscle cells of a bird and a mammal. Our data show that, although Glu-Lys bonds occur in low concentrations in cellular proteins, they are nevertheless widely distributed. Evidence is also presented indicating that the low levels of the Glu-Lys bonds we measure in the proteins of various cells types are not artifacts of our analytical procedures.