Enzymatic sulfation of coelenterazine by human cytosolic aryl sulfotransferase SULT1A1: identification of coelenterazine C2-benzyl monosulfate by LC/ESI-TOF-MS.

Coelenterazine (CTZ) is known as a light-emitting source for the bioluminescence reaction in marine organisms. CTZ has two phenolic hydroxy groups at the C2-benzyl and C6-phenyl positions, and a keto-enol type hydroxy group at the C3-position in the core structure of imidazopyrazinone (= 3,7-dihydroimidazopyrazin-3-one). These hydroxy groups in CTZ could be sulfated by sulfotransferase(s), and the sulfates of Watasenia luciferin (CTZ disulfate at the C2- and C6-positions) and Renilla pre-luciferin (CTZ 3-enol sulfate) have been identified in marine organisms. To characterize the sulfation process of CTZ, human cytosolic aryl sulfotransferase SULT1A1 (SUTase) was used as a model enzyme. The sulfated products catalyzed by SUTase with 3'-phosphoadenosine 5'-phosphosulfate (PAPS) were analyzed by LC/ESI-TOF-MS. The product was the monosulfate of CTZ and identified as the C2-benzyl sulfate of CTZ (CTZ C2-benzyl monosulfate), but CTZ disulfate, CTZ 3-enol sulfate, and CTZ C6-phenyl monosulfate were not detected. The non-enzymatic oxidation products of dehydrocoelenterazine (dCTZ, dehydrogenated derivative of CTZ), coelenteramide (CTMD), and coelenteramine (CTM) from CTZ were also identified as their monosulfates.

Novel Algorithm for the Estimation of Cancer Incidence Using Claims Data in Japan: A Feasibility Study.

PURPOSE: We developed algorithms to identify patients with newly diagnosed cancer from a Japanese claims database to identify the patients with newly diagnosed cancer of the sample population, which were compared with the nationwide cancer incidence in Japan to assess the validity of the novel algorithms. METHODS: We developed two algorithms to identify patients with stomach, lung, colorectal, breast, and cervical cancers: diagnosis only (algorithm 1), and combining diagnosis, treatments, and medicines (algorithm 2). Patients with newly diagnosed cancer were identified from an anonymized commercial claims database (JMDC Claims Database) in 2017 with two inclusions/exclusion criteria: selecting all patients with cancer (extract 1) and excluding patients who had received cancer treatments in 2015 or 2016 (extract 2). We estimated the cancer incidence of the five cancer sites and compared it with the Japan National Cancer Registry incidence (calculated standardized incidence ratio with 95% CIs). RESULTS: The number of patients with newly diagnosed cancer ranged from 219 to 17,840 by the sites, algorithms, and exclusion criteria. Standardized incidence ratios were significantly higher in the JMDC Claims Database than in the national registry data for extract 1 and algorithm 1, extract 1 and algorithm 2, and extract 2 and algorithm 1. In extract 2 and algorithm 2, colorectal cancer in male and stomach, lung, and cervical cancers in females showed similar cancer incidence in the JMDC and national registry data. CONCLUSION: The novel algorithms are effective for extracting information about patients with cancer from claims data by using the combined information on diagnosis, procedures, and medicines (algorithm 2), with 2-year cancer-treatment history as an exclusion criterion (extract 2).

Efficient conversion to Cypridina luciferin from Cypridina luciferyl sulfate, coupled with enzymatic sulfation of acetic acid.

In Cypridina (Vargula) hilgendorfii, Cypridina luciferin is converted from Cypridina luciferyl sulfate by a sulfotransferase with adenosine 3', 5'-diphosphate (PAP), and is used for the luminescence reaction of Cypridina luciferase. We found that the luminescence activity of crude extracts of C. hilgendorfii was significantly stimulated by the addition of acetic acid. This stimulation may be explained by an efficient supply of PAP from 3'-phosphoadenosine 5'-phosphosulfate (PAPS) catalyzed by a sulfotransferase. Thus, acetic acid acts as a sulfate acceptor from PAPS, followed by forming acetyl sulfate and PAP. The structure of acetyl sulfate was identified using mass spectrometry and it spontaneously decomposed to acetic acid and free sulfate ion in aqueous solutions. This enzymatic conversion from Cypridina luciferyl sulfate to Cypridina luciferin could be coupled with acetic acid and PAPS by a sulfotransferase.

Enzymatic Conversion of Cypridina Luciferyl Sulfate to Cypridina Luciferin with Coenzyme A as a Sulfate Acceptor in Cypridina (Vargula) hilgendorfii.

In the luminous ostracod Cypridina (presently Vargula) hilgendorfii, Cypridina luciferyl sulfate (3-enol sulfate of Cypridina luciferin) is converted to Cypridina luciferin by a sulfotransferase with 3'-phosphoadenosine-5'-phosphate (PAP) as a sulfate acceptor. The resultant Cypridina luciferin is used for the luciferase-luciferin reaction of Cypridina to emit blue light. The luminescence stimulation with major organic cofactors was examined using the crude extracts of Cypridina specimens, and we found that the addition of coenzyme A (CoA) to the crude extracts significantly stimulated luminescence intensity. Further, the light-emitting source in the crude extracts stimulated with CoA was identified as Cypridina luciferyl sulfate, and we demonstrated that CoA could act as a sulfate acceptor from Cypridina luciferyl sulfate. In addition, the sulfate group of Cypridina luciferyl sulfate was also transferred to adenosine 5'-monophosphate (5'-AMP) and adenosine 3'-monophosphate (3'-AMP) by a sulfotransferase. The sulfated products corresponding to CoA, 5'-AMP and 3'-AMP were identified using mass spectrometry. This is the first report that CoA can act as a sulfate acceptor in a sulfotransferase reaction.