Abstract:
:The instantaneous electrochromic response of carotenoids associated with the B800-850 light-harvesting complex of Rhodobacter sphaeroides has been used widely as an intrinsic probe of membrane potential. In the present study, the structural basis for this phenomenon was examined by phospholipase A2 digestion of chromatophores from R. sphaeroides strain NF57G, containing B800-850 as the sole pigment-protein complex. The major phospholipase-induced alterations of the overall carotenoid absorption spectrum were characterized by an absorbance loss and a blue shift that were accompanied by a decrease in absorbance at 800 nm and a red shift in the B850 absorbance band. In wild-type chromatophores, the electrochromic carotenoid response induced by both flash illumination and a K+ diffusion potential was diminished by approximately 60% after 1 h of digestion. The initial loss of the carotenoid response was correlated specifically to the hydrolysis of phosphatidylethanolamine, and was shown to arise from effects exerted directly upon the electrochromically active carotenoid pool, possibly by alterations in the spatial relationship between the field-sensitive carotenoids and the polarizing permanent field. In phospholipase A2-digested NF57G preparations in which the B800 band was diminished by nearly half and the carotenoid response was abolished, no significant changes in the efficiency of energy transfer from carotenoids to bacteriochlorophyll were detected at 77 K, suggesting that the electrochromically active carotenoids are not energetically linked to B800 bacteriochlorophyll.
journal_name
Biochemistryjournal_title
Biochemistryauthors
Olivera LM,Niederman RAdoi
10.1021/bi00054a017subject
Has Abstractpub_date
1993-01-26 00:00:00pages
858-66issue
3eissn
0006-2960issn
1520-4995journal_volume
32pub_type
杂志文章相关文献
BIOCHEMISTRY文献大全abstract::All-trans-retinol is the precursor for all-trans-retinoic acid, the activating ligand for nuclear transcription factors retinoic acid receptors. In the cytosol of various cells, most retinol exists in a bound form, complexed with cellular retinol binding protein type I (holo-CRBP). Whether retinoic acid is produced fr...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi026836r
更新日期:2003-01-28 00:00:00
abstract::Tissue plasminogen activator-inhibitor complexes were purified from the conditioned medium of human umbilical vein endothelial cells by affinity chromatography followed by gel filtration. It was found that a single complex was isolated which can exist in two distinct interconvertible conformations. These may be separa...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00397a037
更新日期:1987-11-17 00:00:00
abstract::Site-directed mutagenesis, electron microscopy, and X-ray crystallography were used to probe the structural basis of annexin IV-induced membrane aggregation and the inhibition of this property by protein kinase C phosphorylation. Site-directed mutants that either mimic (Thr6Asp, T6D) or prevent (Thr6Ala, T6A) phosphor...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi002507s
更新日期:2001-04-03 00:00:00
abstract::Yah1p, an [Fe 2S 2]-containing ferredoxin located in the matrix of Saccharomyces cerevisiae mitochondria, functions in the synthesis of Fe/S clusters and heme a prosthetic groups. EPR, Mossbauer spectroscopy, and electron microscopy were used to characterize the Fe that accumulates in Yah1p-depleted isolated intact mi...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi801047q
更新日期:2008-09-16 00:00:00
abstract::Fatty acid amide hydrolase (FAAH) is an integral membrane enzyme that degrades the fatty acid amide family of signaling lipids, including the endocannabinoid anandamide. Genetic or pharmacological inactivation of FAAH leads to analgesic, anti-inflammatory, anxiolytic, and antidepressant phenotypes in rodents without s...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi701378g
更新日期:2007-11-13 00:00:00
abstract::Phosphatidylcholine phospholipase C (EC 3.1.4.3) from Bacillus cereus has been assayed with substrates in the form of large unilamellar vesicles. Phosphatidylcholine, phosphatidylethanolamine (also a substrate for the enzyme), sphingomyelin, and cholesterol have been mixed in various proportions, in binary, ternary, a...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi980615x
更新日期:1998-08-18 00:00:00
abstract::CD6 is a member of the scavenger receptor cysteine rich protein superfamily (SRCRSF). This family includes many cell surface proteins whose three-dimensional structures and functions are presently not well understood. The extracellular region of CD6 includes 3 SRCR domains. The membrane proximal SRCR domain specifical...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi962560+
更新日期:1997-03-04 00:00:00
abstract::Circumsporozoite (CS) protein is a predominant surface antigen of malaria sporozoites, the infective form of the parasite, and has been used for making anti-malaria vaccines. For the first time we have examined the interaction of CS protein with various glycosaminoglycans in real time using surface plasmon resonance (...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0105476
更新日期:2001-09-25 00:00:00
abstract::Changes in pH can alter the structure and activity of proteins and may be used by the cell to control molecular function. This coupling can also be used in non-native applications through the design of pH-sensitive biomolecules. For example, the pH (low) insertion peptide (pHLIP) can spontaneously insert into a lipid ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.6b00380
更新日期:2016-08-09 00:00:00
abstract::Phospholipase Cβ (PLCβ) enzymes hydrolyze phosphatidylinositol 4,5-bisphosphate to produce second messengers that regulate intracellular Ca2+, cell proliferation, and survival. Their activity is dependent upon interfacial activation that occurs upon localization to cell membranes. However, the molecular basis for how ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.7b00547
更新日期:2017-10-17 00:00:00
abstract::Nanosecond to millisecond conformational fluctuations of Zn-substituted cytochrome c (ZnCytc) have been studied by the time-resolved transient hole-burning method. The investigation of low-temperature dynamics has been made on the ZnCytc solution sample in a water-glycerol mixture. The conformational fluctuations in t...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi981568b
更新日期:1999-02-09 00:00:00
abstract::Abortive transcription initiation can be rate-limiting for promoter escape and therefore represents a barrier to productive gene expression. The mechanism for abortive initiation is unknown, but the amount of abortive transcript is known to vary with the composition of the initial transcribed sequence (ITS). Here, we ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.5b00272
更新日期:2015-07-21 00:00:00
abstract::Casein kinase II (CKII) is a ubiquitous protein kinase, found predominantly in cell nuclei, which has two subunits in a tetrameric alpha 2 beta 2 or alpha alpha' beta 2 conformation. The catalytic center is present in the alpha subunit which is active by itself while beta is a regulatory subunit that can greatly enhan...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00079a030
更新日期:1993-07-20 00:00:00
abstract::Thioredoxin reductase (TrxR) catalyzes the reduction of thioredoxin (Trx) by NADPH. A unique gene organization of TrxR and Trx has been found in Mycobacterium leprae, where TrxR and Trx are encoded by a single gene and, therefore, are expressed as a fusion protein (MlTrxR-Trx). This fusion enzyme is able to catalyze t...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi980754e
更新日期:1998-11-17 00:00:00
abstract::Retinal rod and cone cGMP phosphodiesterases (PDE6 family) function as the effector enzyme in the vertebrate visual transduction cascade. The activity of PDE6 catalytic subunits is controlled by the Pgamma-subunits. In addition to the inhibition of cGMP hydrolysis at the catalytic sites, Pgamma is known to stimulate a...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi015935m
更新日期:2002-03-26 00:00:00
abstract::One- and two-dimensional NMR experiments were carried out on a decamer, d-(CGCTTTTCGC).d(GCGAAAAGCG), and on the same sequence with the addition of an unpaired thymidine, d(CGCTTTTCGC).d(GCGAATAAGCG), which will be referred to as the T-bulge decamer. Evidence from one-dimensional NOE experiments on the exchangeable pr...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00489a047
更新日期:1990-09-18 00:00:00
abstract::We have measured the rates and efficiencies of DNA unwinding (the number of ATP molecules hydrolyzed per DNA base pair unwound) catalyzed by the RecBC,RecBCD-K177Q (a site-directed mutant in the putative ATP-binding site in the RecD subunit), and RecBCD enzymes from Escherichia coli. The DNA unwinding rate was measure...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00198a022
更新日期:1994-08-16 00:00:00
abstract::We examined the metabolism of exogenously added 13C-labeled fructose 1,6-bisphosphate (either labeled at the first and sixth carbons or labeled at the first carbon only) and of [2-13C]glucose in well-oxygenated and well-superfused hog carotid artery segments. Exogenously added fructose 1,6-bisphosphate was utilized by...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00004a027
更新日期:1995-01-31 00:00:00
abstract::Apical membrane antigen 1 (AMA1) of the human malaria parasite Plasmodium falciparum is synthesized by schizont stage parasites and has been implicated in merozoite invasion of host erythrocytes. Phage-display techniques have recently been used to identify two 15-residue peptides, F1 and F2, which bind specifically to...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi034376b
更新日期:2003-08-26 00:00:00
abstract::The discovery of three mutants in the -synuclein (alphaSyn) gene and the identification of alphaSyn as the major component of Lewy body have opened a new field for understanding the pathogenesis of Parkinson's disease (PD). AlphaSyn is a natively unfolded protein with unknown function and unspecified conformational he...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi062068i
更新日期:2007-01-16 00:00:00
abstract::The lipid fatty acid composition of the cytoplasmic membranes of Escherichia coli can be varied by growing an unsaturated fatty acid auxotroph in the presence of different fatty acid supplements. Electron spin resonance (ESR) studies of spin-label partitioning into the cytoplasmic membranes of different lipid fatty ac...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00627a015
更新日期:1977-04-19 00:00:00
abstract::The noncovalent interaction of 2-aminodipyrido[1,2-a:3',2'-d]imidazole (Glu-P-2) and its derivatives, which are potent mutagens isolated from L-glutamic acid pyrolysate, with calf thymus DNA was studied by steady-state and nanosecond fluorescence spectroscopies. The fluorescence of these compounds exhibits static quen...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00344a013
更新日期:1985-11-05 00:00:00
abstract::Strong inward-rectifier K(+) (Kir) channels play a significant role in shaping the cardiac action potential: they help produce its long plateau and accelerate its rate of repolarization. Consequently, genetic deletion of the gene encoding the strongly rectifying K(+) channel IRK1 (Kir2.1) prolongs the cardiac action p...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0483099
更新日期:2004-12-14 00:00:00
abstract::Nhp6A is an abundant non-histone chromatin-associated protein in Saccharomyces cerevisiae that contains a minor groove DNA binding motif called the HMG box. In this report, we show that Nhp6Ap binds to cisplatin intrastrand cross-links on duplex DNA with a 40-fold greater affinity than to unmodified DNA with the same ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi012077l
更新日期:2002-04-30 00:00:00
abstract::The structure of MtrA, an essential gene product for the human pathogen Mycobacterium tuberculosis, has been solved to a resolution of 2.1 A. MtrA is a member of the OmpR/PhoB family of response regulators and represents the fourth family member for which a structure of the protein in its inactive state has been deter...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi602546q
更新日期:2007-06-12 00:00:00
abstract::Human insulin-like growth factors I and II (hIGF-I, hIGF-II) are potent stimulators of cell and growth processes. They display high sequence similarity to both the A and B chains of insulin but contain an additional connecting C-domain, which reflects their secretion without specific packaging or precursor conversion....
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi020084j
更新日期:2002-07-30 00:00:00
abstract::Corticosteroid binding globulin (CBG), a serum glycoprotein which binds glucocorticoids and progestins with high affinity, is widely distributed throughout the animal world. Although its charge and size characteristics have largely been conserved across species, we found the behavior of CBG in squirrel monkey (Saimiri...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00407a046
更新日期:1988-04-05 00:00:00
abstract::Phosphoenolpyruvate carboxykinase (PEPCK) is an essential metabolic enzyme operating in the gluconeogenesis and glyceroneogenesis pathways. Previous work has demonstrated that the enzyme cycles between a catalytically inactive open state and a catalytically active closed state. The transition of the enzyme between the...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.5b01215
更新日期:2016-01-26 00:00:00
abstract::Directed hydroxyl radical probing of 16S ribosomal RNA from Fe(II) tethered to specific sites within the RNA was used to determine RNA-RNA proximities in 70S ribosomes. We have transcribed 16S ribosomal RNA in vitro as two separate fragments, covalently attached an Fe(II) probe to a 5'-guanosine-alpha-phosphorothioate...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi981644a
更新日期:1999-01-19 00:00:00
abstract::The bovine adrenodoxin gene gives rise to two species of mRNA differing only at their 5'-ends. The synthesis of these two types of mRNA in bovine adrenal cortical cells is regulated transcriptionally in part by ACTH via the action of cAMP. Examination of the 5'-end of the adrenodoxin gene revealed that each mRNA conta...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00123a027
更新日期:1992-03-03 00:00:00