Fig. 8.
Characterization of LPO knock-out mouse. Deficiency of LPO in LPO-ko mouse was confirmed by the analysis of milk. (A) Western blot analysis of the mice milk. Lane Wild-type, whole milk from wild-type mouse; lane Lpo−/−, whole milk from LPO-ko mouse. An anti-mouse LPO antibody, which cross-reacts with LPO protein in milk fraction from wild-type counterpart (shown as arrow), cannot detect LPO from LPO-ko milk. Each lane contains 5 μg protein. Molecular mass standards (Precision Protein Standards, Bio-Rad Laboratories) (B) Milk XOR activity was compared in wild-type (B6J, n = 3), XDH-stable mutant (B6xdh, n = 3), and LPO-ko (B6lpo, n = 5), mice. XOR activity was measured by the method described in the Materials and methods immediately after milking. Bar graphs show mean ± SD. The total (NAD + plus O2-dependent) urate formation (green bar), O2-dependent urate formation (red bar: XO activity), and NAD+-dependent NADH formation (blue bar: XDH activity) were indicated as a percentage value of the total urate formation activity. (For interpretation of the references to color in this figure legend, the reader is referred to the Web version of this article.)