Isolation and characterisation of a novel rabbit sulfotransferase isoform belonging to the SULT1A subfamily

Genetic diversity of the sulfotransferase-like gene and one nonsynonymous SNP associated with growth traits of clam, Meretrix meretrix

The sulfotransferase (SULT) is an important factor in phase II metabolism. Three single nucleotide polymorphisms (SNPs; MmeSUl-696, MmeSUl-714 and MmeSUl-806) were discovered in a SULT-like gene of Meretrix meretrix. A modified allele-specific PCR detection assay was developed to perform polymorphism analysis of the three SNPs in two families and two populations of M. meretrix. Results showed that the genotype of the three SNPs is accordance to the expected Mendelian segregation ratios and conforms to Hardy-Weinberg Equilibrium (HWE) in families and populations, respectively. Moreover, sampled clams (n = 151) from the two populations were tested for the associations between SNPs and growth traits. The single SNP association analysis indicated MmeSUl-806 significantly (P < 0.05) correlated with growth traits of M. meretrix. A further haplotype-trait association analysis confirmed that the three SNPs were in linkage disequilibrium and showed that the haplotype TTG and TCG associated with low growth in the two populations, respectively, which supported that MmeSUl-806 was a growth related marker. This study suggested SULT gene might be a candidate gene related to growth in bivalves and MmeSUl-806 could be a gene marker in linkage map construction and breeding programs of M. meretrix.

Pharmacokinetic parameters and a theoretical study about metabolism of BR-AEA (a salbutamol derivative) in rabbit

In this study, we report the pharmacokinetics of 1-(4-di-hydroxy-3,5-dioxa-4-borabicyclo[4.4.0]deca-7,9,11- trien-9-yl)-2-(tert-butylamino)ethanol (BR-AEA). This compound was identified as a more potent beta(2) adrenoceptor (beta(2)AR) agonist than salbutamol. A sensitive and reproducible high-performance liquid chromatography (HPLC) method was used for determining the time-dependent BR-AEA concentration in healthy rabbit plasma. The pharmacokinetic parameters obtained are explained in relation to the compound's metabolism by sulfotransferases. For this purpose, docking simulations were carried out on SULT1A3, SULT1C1, and SULT1A1 3-D models using the Autodock 3.0.5 program. According to the HPLC results, t(1/2) = 2.36 +/- 0.18 h and K(e) = 0.32 +/- 0.02 h(-1) for BR-AEA in rabbit plasma. Thus, BR-AEA has a greater half-life compared with salbutamol (t(1/2) = 0.66 +/- 0.08 h). This could be due to the protection that the boronic acid moiety of BR-AEA offers to the hydroxyl groups that would otherwise be susceptible to sulfation when exposed inside the active site of the sulfotransferase. This could be due to the fact that BR-AEA has a high affinity for the side-chain hydroxyl groups of Ser and Tyr residues of the enzymes, which are located outside the active site.

Substrate characterisation of a recombinant sulfotransferase SULT1 and mRNA expression in chub (Leuciscus cephalus) tissues

We have studied the role and regulation of sulfonation of xenobiotics and endogenous substrates in Leuciscus cephalus, an abundant and environmentally relevant freshwater fish. A sulfotransferase 1 (SULT1) cDNA and promoter region was cloned from chub liver and the cDNA expressed in Escherichia coli. The translated protein displayed 51% and 50% amino acid identity to mSULT1D1, hSULT1A1, respectively. We identified two conserved co-substrate binding motifs for 3'-phosphoadenosine 5'-phosphosulfate: RKGxxGDWKxxFT and YPKSGTxW. The recombinant SULT displayed a strong preference towards the isoflavones genistein (K(m)=1.7 microM) and daidzein (K(m)=4.4 microM) and lesser activity towards the endogenous substrate dopamine. Based on sequence identity and substrate preferences, the SULT was classified as SULT1,3. SULT1,3 mRNA expression was highest in the liver and kidney with low levels expressed in brain, gonad, and gill. Mature males displayed higher hepatic SULT1,3 mRNA expression compared to females. Analysis of the promoter region revealed several putative half palindromic estrogen response elements (ERE).

Sulfation and glucuronidation of phenols: implications in coenyzme Q metabolism

Phase II conjugation of phenolic compounds constitutes an important mechanism through which exogenous or endogenous toxins are detoxified and excreted. Species differences in the rates of glucuronidation or sulfation can lead to significant variation in the metabolism of this class of compounds. Conjugation of the hydroxyl groups of phenols can occur with glucuronate or sulfate. Quinone metabolism, deactivation, and detoxification are also affected by the same conjugatory systems as phenols; however, reduction of quinones to hydroquinols seems to be a prerequisite. This work reviews current knowledge on phenol conjugation and its implications on hydroquinone metabolism with special consideration for coenzyme Q metabolism.

A proposed nomenclature system for the cytosolic sulfotransferase (SULT) superfamily

A nomenclature system for the cytosolic sulfotransferase (SULT) superfamily has been developed. The nomenclature guidelines were applied to 65 SULT cDNAs and 18 SULT genes that were characterized from eukaryotic organisms. SULT cDNA and gene sequences were identified by querying the GenBank databases and from published reports of their identification and characterization. These sequences were evaluated and named on the basis of encoded amino acid sequence identity and, in a few cases, a necessity to maintain historical naming convention. Family members share at least 45% amino acid sequence identity whereas subfamily members are at least 60% identical. cDNAs which encode amino acid sequences of at least 97% identity to each other were assigned identical isoform names. We also attempted to categorize orthologous enzymes between various species, where these have been identified, and the nomenclature includes a species descriptor. We present recommendations for the naming of allelic variants of SULT genes and their derived allozymes arising from single nucleotide polymorphisms and other genetic variation. The superfamily currently comprises 47 mammalian SULT isoforms, one insect isoform and eight plant enzymes, and collectively these sequences represent nine separate SULT families and 14 subfamilies. It is hoped that this nomenclature system will be widely adopted and that, as novel SULTs are identified and characterized, investigators will name their discoveries according to these guidelines.