PMID- 28889295 OWN - NLM STAT- MEDLINE DCOM- 20180511 LR - 20180813 IS - 1940-6029 (Electronic) IS - 1064-3745 (Linking) VI - 1657 DP - 2017 TI - Analysis of c-di-GMP Levels Synthesized by a Photoreceptor Protein in Response to Different Light Qualities Using an In Vitro Enzymatic Assay. PG - 187-204 LID - 10.1007/978-1-4939-7240-1_15 [doi] AB - Diguanylate cyclases are enzymes that use two GTP molecules to produce one molecule cyclic dimeric guanosine monophosphate (c-di-GMP). This cyclic dinucleotide is an ubiquitous prokaryotic second messenger that controls a variety of cell functions. Several proteins have been described which contain a photoreceptor domain fused to a diguanylate cyclase. The cyanobacterial light sensor Cph2 is responsible for the blue-light induced synthesis of c-di-GMP in Synechocystis sp. PCC 6803. Here, we provide a detailed protocol for an in vitro enzymatic assay with a purified photoreceptor protein using light as the crucial reaction parameter for c-di-GMP synthesis. The assay is accomplished under continuous illumination with light of different quality with inactivation of the enzyme by heat denaturation. Analytics are performed using HPLC-UV. FAU - Angerer, Veronika AU - Angerer V AD - Institute of Biology III, Albert-Ludwigs-University Freiburg, Schanzlestr. 1, 79104, Freiburg, Germany. FAU - Essen, Lars-Oliver AU - Essen LO AD - Department of Chemistry, Philipps-University Marburg, 35032, Marburg, Germany. FAU - Wilde, Annegret AU - Wilde A AD - Institute of Biology III, Albert-Ludwigs-University Freiburg, Schanzlestr. 1, 79104, Freiburg, Germany. annegret.wilde@biologie.uni-freiburg.de. LA - eng PT - Journal Article PT - Research Support, Non-U.S. Gov't PL - United States TA - Methods Mol Biol JT - Methods in molecular biology (Clifton, N.J.) JID - 9214969 RN - 0 (Bacterial Proteins) RN - 61093-23-0 (bis(3',5')-cyclic diguanylic acid) RN - H2D2X058MU (Cyclic GMP) SB - IM MH - Bacterial Proteins/*metabolism MH - Chromatography, High Pressure Liquid MH - Cyanobacteria/*physiology/*radiation effects MH - Cyclic GMP/*analogs & derivatives/biosynthesis/metabolism MH - Enzyme Activation MH - Enzyme Assays/methods/standards MH - *Light MH - Reference Standards MH - Spectrophotometry, Ultraviolet OTO - NOTNLM OT - Cyclic diguanylate OT - Cyclic nucleotide OT - Enzyme-activity assay OT - In vitro enzymatic method OT - Light-dependent enzymatic activity OT - Photosensor OT - Photoswitch OT - Second messenger OT - c-di-GMP EDAT- 2017/09/11 06:00 MHDA- 2018/05/12 06:00 CRDT- 2017/09/11 06:00 PHST- 2017/09/11 06:00 [entrez] PHST- 2017/09/11 06:00 [pubmed] PHST- 2018/05/12 06:00 [medline] AID - 10.1007/978-1-4939-7240-1_15 [doi] PST - ppublish SO - Methods Mol Biol. 2017;1657:187-204. doi: 10.1007/978-1-4939-7240-1_15.