Dataset Information

Large-scale production and purification of the human green cone pigment: characterization of late photo-intermediates.

ABSTRACT: We present the first characterization of the late photo-intermediates (Meta I, Meta II and Meta III) of a vertebrate cone pigment in a lipid environment. Marked differences from the same pathway in the rod pigment were observed. The histidine-tagged human green cone pigment was functionally expressed in large-scale suspension cultures in Sf9 insect cells using recombinant baculovirus. The recombinant pigment was extensively purified in a single step by immobilized metal affinity chromatography and displays the expected spectral characteristics. The purified pigment was able to activate the rod G-protein transducin at about half the rate of the rod pigment. Following reconstitution into bovine retina lipid proteoliposomes, identification and analysis of the photo-intermediates Meta I, Meta II and Meta III was accomplished. Similar to the rod pigment, our results indicate the existence of a Meta I-Meta II equilibrium, but we find no evidence for pH dependence. Replacement of native Cl- by NO3- in the anion-binding site of the cone pigment affected the spectral position of the pigment itself and of the Meta I intermediate, but not that of Meta II and Meta III. The decay rate of the 'active' intermediate Meta II did not differ for the Cl- and NO3- state. However, in qualitative agreement with results reported before for chicken cone pigments, the rate of Meta II decay was significantly higher in the human cone pigment than in the rod pigment.

SUBMITTER: Vissers PM

PROVIDER: S-EPMC1219262 | biostudies-other | 1998 Mar

REPOSITORIES: biostudies-other

ACCESS DATA

Similar Datasets

Project description:Algal photo-bio hydrogen production, a promising method for producing clean and renewable fuel in the form of hydrogen gas, has been studied extensively over the last few decades. In this study, microarray analyses were used to obtain a global expression profile of mRNA abundance in the green alga Chlamydomonas reinhardtii at five different time points before the onset and during the course of sulphur depleted hydrogen production. The present work confirms previous findings on the impacts of sulphur deprivation but also provides new insights into photosynthesis, sulphur assimilation and carbon metabolism under sulphur starvation towards hydrogen production. For instance, while a general trend towards repression of transcripts encoding photosynthetic genes was observed, the abundance of Lhcbm9 (encoding a major light harvesting polypeptide) and LhcSR1 (encoding a chlorophyll binding protein) was strongly elevated throughout the experiment, suggesting remodeling of the photosystem II light harvesting complex as well as an important function of Lhcbm9 under sulphur starvation. This study presents the first global transcriptional analysis of C. reinhardtii during hydrogen production using five major time points at Peak Oxygen, Mid Oxygen, Zero Oxygen, Mid Hydrogen and Peak Hydrogen. Keywords: Time course, sulfur deprivation, hydrogen production. Time course microarray analyses were used to analyze the global gene expression in sulfur depleted hydrogen producing C. reinhardtii. When depleted of sulfur, a sealed an illuminated C. reinhardtii culture slowly becomes anaerobic and produces hydrogen gas. Based on the changes in the dissolved O2 level and H2 production rate, the whole course of H2 production from the starting of S deprivation to the end of H2 production can be divided into five phases including an Aerobic Phase (I) in which the dissolved O2 level goes up (I), an O2 Consumption Phase (II), an Anaerobic Phase (III), a H2 Production Phase (IV) and a Termination phase (V). Samples were taken from three different bioreactors (biological replicates) at the following time points after the start of S depletion: 6 h, 16 h, 21 h, 37 h and 52 h corresponding to Peak O2, Mid O2, Zero O2, Mid H2 and Peak H2.

Dataset Information

Large-scale production and purification of the human green cone pigment: characterization of late photo-intermediates.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets