Nature 255, 422 - 423 (29 May 1975); doi:10.1038/255422a0

More similarity between bakers' yeast L-(+)-lactate dehydrogenase and liver microsomal cytochrome b₅

BERNARD GUIARD, FLORENCE LEDERER & C. JACQ^*

Centre de Génétique Moléculaire, CNRS, 91190 Gif-sur-Yvette, France
^*Present address: MRC Laboratory of Molecular Biology, Hills Road, Cambridge, UK.

BAKERS' yeast L-lactate dehydrogenase, or cytochrome b ₂ (EC 1.1.2.3.), catalyses the oxidation of L-(+)-lactate to pyruvate. When purified in the presence of phenylmethane-sulphonylfluoride, it is a tetramer of four presumably identical polypeptide chains of molecular weight 57,000, each of which carries one flavin mononucleotide and one protohaem IX (ref. 1). In the absence of protease inhibitor, the enzyme obtained by the classical crystallisation method of Appleby and Morton² shows cleavages at the N terminus and at a region about two-thirds down the chain, in each monomer; it is then composed of four chains () of molecular weight about 36,000 and four chains () of about 21,000 (ref. 1).

References

1.	Jacq, C., and Lederer, F., Eur. J. Biochem., 41, 311–320 (1974) and refs therein.
2.	Appleby, C. A., and Morton, R. K., Nature, 173, 749–753 (1954).
3.	Labeyrie, F., Di Franco, A., Iwatsubo, M., and Baudras, A., Biochemistry. 6, 1791–1797 (1967).
4.	Labeyrie, F., Groudinsky, O., Jacquot-Armand, Y., and Naslin, L., Biochim. biophys. Acta, 128, 492–503 (1966).
5.	Watari, H., Groudinsky, O., and Labeyrie, F., Biochim. biophys. Acta, 131, 592–594 (1967).
6.	Keller, R. M., Groudinsky, O., and Wüthrich, K., Biochim. biophys. Acta, 328, 233–238 (1973).
7.	Groudinsky, O., Eur. J. Biochem., 18, 480–484 (1971).
8.	Guiard, B., Groudinsky, O., and Lederer, F., Proc. natn. Acad. Sci. U.S.A., 71, 2539–2543 (1974).
9.	Mevel-Ninio, M., Eur. J. Biochem., 25, 254–261 (1972).
10.	Guiard, B., Groudinsky, O., and Lederer, F., Eur. J. Biochem., 34, 241–247 (1973).
11.	Naslin, L., Spyridakis, A., and Labeyrie, F., Eur. J. Biochem., 34, 268–283 (1973).
12.	Ozols, J., Biochemistry, 13, 426–434 (1974).
13.	Ito, A., and Sato, R., J. biol. Chem., 243, 4922–4923 (1968).
14.	Spatz, L., and Strittmatter, P., Proc. natn. Acad. Sci. U.S.A., 68, 1042–1046 (1971).
15.	Shimakato, T., Mihara, K., and Sato, R., J. Biochem., Tokyo, 72, 1163–1174 (1972).
16.	Strittmatter, P., Rogers, M. J., and Spatz, L., J. biol. Chem., 247, 7188–7194 (1972).
17.	Mathews, F. S., Argos, P., and Levine, M., Cold Spring Harb. Symp. quant. Biol., 35, 387–395 (1971).
18.	Lederer, F., and Simon, A. M., Eur. J. Biochem., 20, 469–474 (1971).
19.	Ozols, J., J. biol. Chem., 247, 2242–2245 (1972).
20.	Atlas of Protein Sequence and Structure (edit. by Dayhoff, M.O.), (National Biomedical Research Foundation, 1972).
21.	Spatz, L., and Strittmatter, P., J. biol. Chem., 248, 793–799 (1973).
22.	Mihara, K., and Sato, R., J. Biochem., 71, 725–735 (1972).