Isolation, partial purification, and characterization of a novel petromyzonol sulfotransferase from Petromyzon marinus (lamprey) larval liver
作者:K.V. Venkatachalam、Domingo E. Llanos、Kristophe J. Karami、Vladimir A. Malinovskii
DOI:10.1194/jlr.m300346-jlr200
日期:2004.3
We have isolated, partially purified, and characterized the 5alpha-petromyzonol (5alpha-PZ), (5alpha-cholan- 3alpha, 7alpha, 12alpha, 24-tetrahydroxy-) sulfotransferase (PZ-SULT) from larval lamprey liver. Crude liver extracts exhibited a PZ-SULT activity of 0.9120 pmol/min/mg in juvenile and 12.62 pmol/min/mg in larvae. Using crude larval liver extracts and various 5 beta-cholan substrates and allocholic acid there was negligible activity, however, with 5alpha-PZ and 3-keto-5alpha-PZ the SULT activity was 231.5 pmol/min/mg and 180.8 pmol/min/mg respectively. This established that the sulfotransferase of lamprey larval liver extracts prefers (5 alpha) substrates and it is selective for hydroxyl at C-24. PZ-SULT was purified through various chromatography procedures. Partially purified PZ-SULT exhibited a pH optimum of 8.0, a temperature optimum of 22degreesC, and activity was linear for 1h. PZ-SULT exhibited a K-m of 2.5 muM for PAPS and a K-m of 8 muM for PZ. The affinity purified peak PZ-SULT exhibited a specific activity of 2,038 pmol/min/mg. The peak protein upon SDS-PAGE, correlated to an Mw 47 kDa. Photoaffinity labeling with PAP(35)S, specifically crosslinked the 47 kDa protein, further confirming the identity of PZ-SULT. Partial amino acid sequencing of the putative 47 kDa PZ-SULT protein yielded a peptide sequence (M)SISQAVDAAFXEI, which possessed an overall (similar to35-40%) homology with mammalian SULT2B1a.-Venkatachalam, K. V., D. E. Llanos, K. J. Karami, and V. A. Malinovskii. Isolation, partial purification, and characterization of a novel petromyzonol sulfotransferase from Petromyzon marinus (lamprey) larval liver.