Fig. 5. Results of efforts to deduce the organization of the mLOC using immunoprecipitation (IP) technology.

In the upper panel, representative immunoblots (IB) are shown using anti-COX, NADH-dh, LDH, or nIgG as precipitating antibodies (IPs). COX, NADH-DH, LDH, and nIgG were immunoprecipitated from mitochondrial fractions of L6 cells resuspended in a suspension medium without detergent. COX IP proteins were probed with MCT1, CD147, and LDH antibodies. MCT1, CD147, and LDH were coprecipitated with COX. NADH-dh IP pellets were probed with MCT1, COX, CD147, and LDH antibodies. Neither MCT1, CD147, nor LDH coprecipitated with NADH-DH, whereas COX coprecipitated with anti-NADH-dh. LDH IP proteins were probed with MCT1 and COX antibodies. Both MCT1 and COX coprecipitated with LDH. No protein coprecipitated with nIgG from mitochondrial fractions of L6 cells resuspended in medium without detergent (negative control). In the lower panel, the degree of coprecipitation evaluated by comparing signals in the IP and the lysate is shown. The results were categorized into four levels: +++, 80% or more precipitated; ++, ∼50% precipitated; +, 20% or less precipitated; -, no precipitation. IB immunoblot, IP immunoprecipitation. From Hashimoto et al.¹³⁸.