Lm. Suneetha et al., PROTEIN-PHOSPHORYLATION IN HUMAN PERIPHERAL-NERVE - ALTERED PHOSPHORYLATION OF A 25-KDA GLYCOPROTEIN IN LEPROSY, Neurochemical research, 21(6), 1996, pp. 707-712
Protein phosphorylation in a low speed supernatant of human peripheral
nerve (tibial and sural) homogenate was investigated. The major phosp
horylated proteins had molecular mass in the range of 70, 55, 45, and
25 kDa. Mg2+ or Mn2+ was essential for maximum phosphorylation althoug
h Zn2+, Co2+, and Ca2+ could partially support phosphorylation. Extern
al protein substrates casein and histone were also phosphorylated. The
protein phosphatase inhibitor orthovanadate enhanced the phosphorylat
ion of the 45 and 25 kDa proteins significantly. Concanavalin A-Sephar
ose chromatography of the phosphorylated peripheral nerve proteins sho
wed that the 25 kDa protein was a glycoprotein. Protein phosphorylatio
n of peripheral nerves from leprosy affected individuals was compared
with normals. The phosphorylation of 25 kDa protein was decreased in m
ost of the patients with leprosy.