Abstract:
:The organization and interaction of chlorophylls (Chl) and the kinetics of the energy transfer in the core antenna of photosystem I (PSI) trimeric and monomeric complexes, isolated from Spirulina platensis with Triton X-100 have been studied by stationary and time-resolved fluorescence. At 295 K both complexes show an unusually intense long-wavelength emission band with prominent peaks at 730 nm (trimers) or 715 nm (monomers), whose intensity is independent of the redox state of P700. A broad band extending from 710 to 740 nm in the absorption and fluorescence excitation spectra of trimers also indicates the existence of the longwave Chls at 295 K. The 77 K fluorescence emission of PSI trimers frozen after addition of dithionite under illumination (P700 and the PSI acceptor side reduced) shows an intense band at 760 (F760) and a smaller one at 725 nm (F725); when P700 is oxidized, the intensity of F760 decreases about 15 times. In the 77 K spectrum of monomers only F725 is present in the longwave region, and its intensity does not depend on the redox state of P700. Bands of Chls with maxima near 680, 710, and 738 nm were found in the 77 K excitation spectrum of trimers, and bands near 680 and 710 nm were seen in the spectrum of monomers. Five spectrally different red Chl forms in PSI trimers and three red Chl in monomers have been resolved by deconvolution of their 77 K absorption spectra. The difference absorption spectrum, trimers-minus-monomers, shows that the appearance of the 735 nm band in trimers is accompanied by a decrease of 708, 698, and 688 nm bands present in monomers. The reversible changes of F760 intensity of Spirulina membranes as a result of their salt treatment confirm the idea that the most longwave Chl form originates from an interaction of Chls bound to different monomeric PSI subunits forming the trimer. The time-resolved fluorescence spectra of PSI trimers and monomers, measured at 287 K in the region 680-770 nm, are substantially different, although a set of similar lifetimes (9, approximately 30, approximately 66, and 1400-2200 ps) was necessary for a good fit. No effect of P700 redox state was observed on the fluorescence kinetics of both complexes at 287 K.
journal_name
Biochemistryjournal_title
Biochemistryauthors
Karapetyan NV,Dorra D,Schweitzer G,Bezsmertnaya IN,Holzwarth ARdoi
10.1021/bi970386zsubject
Has Abstractpub_date
1997-11-11 00:00:00pages
13830-7issue
45eissn
0006-2960issn
1520-4995pii
bi970386zjournal_volume
36pub_type
杂志文章相关文献
BIOCHEMISTRY文献大全abstract::Carboxylation of vitamin K-dependent (VKD) proteins is required for their activity and depends on reduced vitamin K generated by vitamin K oxidoreductase (VKOR) and a redox protein that regenerates VKOR activity. VKD protein carboxylation is inefficient in mammalian cells, and to understand why carboxylation becomes s...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi051986y
更新日期:2006-05-02 00:00:00
abstract::The structural underpinnings of enzyme substrate specificity are investigated in a pair of copper amine oxidases (CAOs) from Hansenula polymorpha (HPAO-1 and HPAO-2). The X-ray crystal structure (to 2.0 A resolution) and steady state kinetic data of the second copper amine oxidase (HPAO-2) are presented for comparison...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi901933d
更新日期:2010-03-23 00:00:00
abstract::The ribonucleoprotein ribonuclease P (RNase P) cleaves all tRNA precursors endonucleolitically to produce the mature 5'-end. Dictyostelium discoideum RNase P displays an absolute requirement for Mg2+. Only the alkaline earth cations Ca2+, Sr2+, and Ba2+, under appropriate conditions can substitute to some extent for M...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi9808971
更新日期:1998-11-03 00:00:00
abstract::PT-ACRAMTU ([PtCl(en)(ACRAMTU-S)](NO(3))(2), en = ethane-1,2-diamine, ACRAMTU = 1-[2-(acridin-9-ylamino)ethyl]-1,3-dimethylthiourea) is a cytotoxic platinum-acridine conjugate previously shown to form adducts with the N3 endocyclic nitrogen of adenine in the DNA minor groove. This unusual observation and our prior det...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi050745n
更新日期:2005-08-23 00:00:00
abstract::CDPKs are a family of calcium (Ca2+)-dependent protein kinases which are defined by a carboxyl-terminal calmodulin-like domain. Mutational analysis indicates that the junction domain, which joins the kinase and calmodulin-like domains, contains an autoinhibitor. CDPK isoform AK1 from Arabidopsis was expressed in Esche...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00189a031
更新日期:1994-06-14 00:00:00
abstract::Past evidence has indicated that Mycobacterium gordonae, as isolated from soil and as an occasional opportunistic pathogen, exists as a serocomplex. We now demonstrate that the basis of seroreactivity and diversity is a novel series of alkali-labile, trehalose-containing lipooligosaccharides (LOS). The structures from...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00210a020
更新日期:1993-11-30 00:00:00
abstract::The light harvesting 1 antenna (LH1) complex from Rhodobacter sphaeroides funnels excitation energy to the photosynthetic reaction center. Our ultimate goal is to build up the structure of LH1 from structures of its individual subunits, much as the antenna can self-assemble from its components in membrane-mimicking de...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi011576j
更新日期:2002-01-08 00:00:00
abstract::Fluorescent nucleobase analogues are used extensively to probe the structure and dynamics of nucleic acids. The fluorescence of the adenine analogue 2-aminopurine and the cytosine analogue pyrrolocytosine is significantly quenched when the bases are located in regions of double-stranded nucleic acids. To allow more de...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi060479t
更新日期:2006-08-01 00:00:00
abstract::Structural and dynamic properties of the self-complementary decadeoxyribonucleotide d(CGCAATTGCG)2 and the interaction between a prototype lexitropsin, or information-reading oligopeptide, and the decadeoxyribonucleotide are deduced by using high-resolution 1H NMR techniques. The nonexchangeable and imino proton reson...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00401a066
更新日期:1988-01-12 00:00:00
abstract::Plasmids containing a site-specifically incorporated O6-methyl- (m6G), O6-ethyl- (e6G), or O6-benzylguanine (b6G) within the ATG initiation codon of the lacZ' gene were used to transform Escherichia coli that were repair proficient or deficient in one or both of the E. coli O6-alkylguanine-DNA alkyltransferases, the u...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00197a020
更新日期:1994-08-09 00:00:00
abstract::The bifunctional reagent p-[(bromoacetyl)-amino]phenyl arsenoxide (BrCH2CONHPhAsO) in the presence of excess reduced nicotinamide adenine dinucleotide has been shown to cause the irreversible active site directed inactivation of the lipoamide dehydrogenase (E3) component of the pyruvate dehydrogenase multienzyme (PD) ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00515a018
更新日期:1981-06-09 00:00:00
abstract::The EcoRV restriction/modification system consists of two enzymes that recognize the DNA sequence GATATC. The EcoRV restriction endonuclease cleaves DNA at this site, but the DNA of Escherichia coli carrying the EcoRV system is protected from this reaction by the EcoRV methyltransferase. However, in vitro, the EcoRV n...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00500a003
更新日期:1990-12-04 00:00:00
abstract::Osmoregulatory transporters stimulate bacterial growth by mediating osmoprotectant uptake in response to increasing osmotic pressure. The ProP protein of Escherichia coli transports proline and other osmoprotectants. Like LacY, ProP is a member of the major facilitator superfamily and a H(+)-solute symporter. ProP is ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi101281f
更新日期:2010-10-19 00:00:00
abstract::The reactions of Rhodopseudomonas viridis cytochrome c2 and horse cytochrome c with Rps. viridis photosynthetic reaction centers were studied by using both single- and double-flash excitation. Single-flash excitation of the reaction centers resulted in rapid photooxidation of cytochrome c-556 in the cytochrome subunit...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00219a021
更新日期:1991-02-05 00:00:00
abstract::Modified (Arg63-Ile64 reactive-site peptide bond hydrolyzed) soybean trypsin inhibitor (Kunitz) with all reactive amino groups, except that of Ile64, protected was described in the preceding paper (Kowalski, D., and Laskowski, M., Jr. (1976), Biochemistry, preceding paper in this issue). Treatment of this inhibitor wi...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00651a022
更新日期:1976-03-23 00:00:00
abstract::Porcine aortic myosin is a smooth muscle contractile protein similar to its striated muscle counterpart. Electrophoresis in sodium dodecyl sulfate indicates that the molecule consists of three classes of subunits with polypeptide chain molecular weights of 192,000, 19,000, and 15,000. At 277 nm the absorption spectrum...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00576a003
更新日期:1979-05-01 00:00:00
abstract::Non-heme diiron clusters occur in a number of enzymes (e.g., ribonucleotide reductase, methane monooxygenase, and Delta9-stearoyl-ACP desaturase) that activate O2 for chemically difficult oxidation reactions. In each case, a kinetically labile peroxo intermediate is believed to form when O2 reacts with the diferrous e...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi981838q
更新日期:1998-10-20 00:00:00
abstract::The interactions of a series of spin-labeled fatty acids, in which the nitroxide ring is incorporated in different ways as an integral part of the hydrocarbon chain, with the (Na+,K+)-ATPase in membranes from Squalus acanthias, have been studied by electron spin resonance spectroscopy. The fatty acids are 2,4-, 2,5-, ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00411a004
更新日期:1988-05-31 00:00:00
abstract::The hydrogen-bonded ring NH nuclear magnetic resonance (NMR) spectra of several transfer ribonucleic acid (RNA) species have been examined with particular emphasis on the extreme low-field portion. Betwen --13.8 and --15 ppm there are two extra resonances which are not derived from cloverleaf base pairs. A combined ap...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00585a025
更新日期:1979-09-04 00:00:00
abstract::Monoamine oxidase (MAO) was shown previously [Silverman, R. B., & Hoffman, S. J. (1980) J. Am. Chem. Soc. 102, 7126-7128] to catalyze the oxidation of N-cyclopropylbenzylamine (N-CBA) at two sites on the molecule. Oxidation at the benzyl methylene gave benzaldehyde and cyclopropylamine; oxidation of the cyclopropyl gr...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00317a019
更新日期:1984-10-23 00:00:00
abstract::We previously showed that beta-amyloid precursor protein (APP) is cleaved not only in the middle of the membrane (gamma-cleavage) but also at novel cleavage sites close to the membrane/cytoplasmic boundary (epsilon-cleavage), releasing APP intracellular domains (AICDs) 49-99 and 50-99. To learn more about the relation...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi049399k
更新日期:2004-10-26 00:00:00
abstract::We extended the technique of frequency-domain fluorometry to an upper frequency limit of 2000 MHz. This was accomplished by using the harmonic content of a laser pulse train (3.76 MHz, 5 ps) from a synchronously pumped and cavity-dumped dye laser. We used a microchannel plate photomultiplier as the detector to obtain ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00375a012
更新日期:1987-01-13 00:00:00
abstract::Glu58 is known to participate in phosphodiester transesterification catalyzed by the enzyme RNase T1. For Glu58 RNase T1, an altered mechanism has been proposed in which His40 replaces Glu58 as the base catalyst [Steyaert, J., Hallenga, K., Wyns, L., & Stanssens, P. (1990) Biochemistry 29, 9064-9072]. Glu58Ala Rnase T...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00173a006
更新日期:1994-02-22 00:00:00
abstract::The FTIR spectra for alkyl isocyanides (CNRs) change from a single nu(CN) band centered at approximately 2175 cm(-1) to two peaks at approximately 2075 and approximately 2125 cm(-1) upon binding to sperm whale myoglobin (Mb). The low- and high-frequency peaks have been assigned to in and out conformations, respectivel...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi100172c
更新日期:2010-06-22 00:00:00
abstract::The reaction of nitric oxide (NO) with fast cytochrome bo from Escherichia coli has been studied by electronic absorption, MCD, and EPR spectroscopy. Titration of the enzyme with NO showed the formation of two distinct species, consistent with NO binding stoichiometries of 1:1 and 2:1 with observed dissociation consta...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi971481a
更新日期:1997-12-23 00:00:00
abstract::The ATP analogue 5'-[p-(fluorosulfonyl)benzoyl]adenosine (FSBA) was used to chemically modify the ATP binding sites of the carbamyl phosphate synthetase domain of CAD, the multifunctional protein that catalyzes the first steps in mammalian pyrimidine biosynthesis. Reaction of CAD with FSBA resulted in the inactivation...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00106a033
更新日期:1991-10-22 00:00:00
abstract::Product distributions for the reaction of glycolaldehyde labeled with carbon-13 at the carbonyl carbon ([1-(13)C]-GA) catalyzed by triosephosphate isomerase (TIM) in D(2)O at pD 7.0 in the presence of phosphite dianion and in its absence were determined by (1)H NMR spectroscopy. We observe three products for the relat...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi900636c
更新日期:2009-06-23 00:00:00
abstract::The association state of the mannitol-specific enzyme II (EIIMtl) has been studied both in the purified form and embedded in the cytoplasmic membrane. Membrane fragments obtained from mannitol-grown Escherichia coli catalyze the phosphoenolpyruvate- (PEP) dependent phosphorylation of both glucose and mannitol; thus th...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00319a003
更新日期:1984-11-20 00:00:00
abstract::Protein arginine methyltransferases (PRMTs) catalyze the transfer of methyl groups from S-adenosylmethionine (SAM) to the guanidinium group of arginine residues in a number of important cell signaling proteins. PRMT1 is the founding member of this family, and its activity appears to be dysregulated in heart disease an...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi102022e
更新日期:2011-04-26 00:00:00
abstract::A major issue for organisms living at extreme temperatures is to preserve both stability and activity of their enzymes. Cold-adapted enzymes generally have a reduced thermal stability, to counteract freezing, and show a lower enthalpy and a more negative entropy of activation compared to mesophilic and thermophilic ho...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi801177k
更新日期:2008-09-23 00:00:00