Figure 2.Muscle creatine kinase (CKm) is differentially 3-nitrotyrosine modified during aging.
Quadriceps muscle extracts (30 ?g) from six young
(3-6 months), six middle-aged (12-14 months) and five aged
(20-24 months) old mice were resolved by SDS PAGE and transferred
to a PVDF membrane. (A) Immunoblots probed with a
monoclonal anti-3-nitrotyrosine antibody reveal a nitrated 45 kDa
protein in middle aged and aged samples. (B) The immunoblots
in (A) were reprobed with an anti-creatine kinase type M
antibody which identifies the levels of CKm in the samples applied
to the gels in (A). (C) Densitometric analysis
demonstrates the progressive increase in nitration in the
aging muscle samples. The highest level of nitration is seen
in the aged muscle samples relative to the young samples.
Error bars depicted on the figure represent calculated standard
errors of mean. p < 0.05 in both cases.
