Abstract:
:We have measured the microsecond rotational motions of myosin heads in contracting rabbit psoas muscle fibers by detecting the transient phosphorescence anisotropy of eosin-5-maleimide attached specifically to the myosin head. Experiments were performed on small bundles (10-20 fibers) of glycerinated rabbit psoas muscle fibers at 4 degrees C. The isometric tension and physiological ATPase activity of activated fibers were unaffected by labeling 60-80% of the heads. Following excitation of the probes by a 10-ns laser pulse polarized parallel to the fiber axis, the time-resolved emission anisotropy of muscle fibers in rigor (no ATP) showed no decay from 1 microsecond to 1 ms (r infinity = 0.095), indicating that all heads are rigidly attached to actin on this time scale. In relaxation (5 mM MgATP but no Ca2+), the anisotropy decayed substantially over the microsecond time range, from an initial anisotropy (r0) of 0.066 to a final anisotropy (r infinity) of 0.034, indicating large-amplitude rotational motions with correlation times of about 10 and 150 microseconds and an overall angular range of 40-50 degrees. In isometric contraction (MgATP plus saturating Ca2+), the amplitude of the anisotropy decay (and thus the amplitude of the microsecond motion) is slightly less than in relaxation, and the rotational correlation times are about twice as long, indicating slower motions than those observed in relaxation. While the residual anisotropy (at 1 ms) in contraction is much closer to that in relaxation than in rigor, the initial anisotropy (at 1 microsecond) is approximately equidistant between those of rigor and relaxation.(ABSTRACT TRUNCATED AT 250 WORDS)
journal_name
Biochemistryjournal_title
Biochemistryauthors
Stein RA,Ludescher RD,Dahlberg PS,Fajer PG,Bennett RL,Thomas DDdoi
10.1021/bi00495a003subject
Has Abstractpub_date
1990-10-30 00:00:00pages
10023-31issue
43eissn
0006-2960issn
1520-4995journal_volume
29pub_type
杂志文章相关文献
BIOCHEMISTRY文献大全abstract::Hepatic mixed-function oxidase metabolism of the ubiquitous pollutant polychlorinated biphenyls (PCBs) is implicated in their toxification and detoxification. We used dichlorobiphenyls (DCBs) as models to investigate the effect of the chloro substituent sites on this metabolism experimentally and by molecular orbital ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00529a009
更新日期:1981-12-22 00:00:00
abstract::The origin of the "S3" EPR signal from calcium-depleted photosystem 2 samples has been investigated. This signal is observed after freezing samples under illumination and has been assigned to an interaction between the manganese cluster and an oxidized histidine radical [Boussac et al. (1990) Nature 347; 303-306]. In ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00134a005
更新日期:1992-05-19 00:00:00
abstract::7,8-diaminopelargonic acid (DAPA) synthase (EC 2.6.1.62) is a pyridoxal phosphate (PLP)-dependent transaminase that catalyzes the transfer of the alpha-amino group from S-adenosyl-L-methionine (SAM) to 7-keto-8-aminopelargonic acid (KAPA) to form DAPA in the antepenultimate step in the biosynthesis of biotin. The wild...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi026339a
更新日期:2002-10-22 00:00:00
abstract::We have determined the structures of three novel oligosaccharides isolated from human milk using the monoclonal antibody MSW 113. These oligosaccharides were purified by affinity chromatography on a column of the immobilized monoclonal antibody and by high-performance liquid chromatography. From the results of 500-MHz...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00448a031
更新日期:1989-10-31 00:00:00
abstract::Cholesterol and its hemisuccinate and sulfate derivatives are widely used in studies of purified membrane proteins but are difficult to solubilize in aqueous solution, even in the presence of detergent micelles. Other cholesterol derivatives do not form conventional micelles and lead to viscous solutions. To address t...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi101334j
更新日期:2010-11-09 00:00:00
abstract::We previously reported that the microtubule (MT)-binding domain of microtubule-associated protein 4 (MAP4) contains three 18-amino acid imperfect repeats that are homologous to the repeats found in the MT-binding domains of the neuronal MAPs, MAP2 and tau [Chapin, S. J., & Bulinski, J. C. (1991) J. Cell Sci. 98, 27-36...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00007a025
更新日期:1995-02-21 00:00:00
abstract::Resonance Raman spectroscopy is employed to characterize heme site structural changes arising from conformational heterogeneity in deoxyMb and ligated derivatives, i.e., the ferrous CO (MbCO) and ferric cyanide (MbCN) complexes. The spectra for the reversed forms of these derivatives have been extracted from the spect...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi801779d
更新日期:2008-12-02 00:00:00
abstract::Drosophila Rrp1 includes a carboxy-terminal region homologous to Escherichia coli exonuclease III which is sufficient to repair both oxidative and alkylation damage to DNA. An apurinic/apyrimidinic endonuclease activity intrinsic to Rrp1 was characterized previously. In this work, the 3'-phosphodiesterase and 3'-phosp...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00004a021
更新日期:1995-01-31 00:00:00
abstract::The cyclic decapeptide antibiotic tyrocidine A was studied by two relatively new methods, viz., correlation proton magnetic resonance (pmr) spectroscopy and double-resonance difference pmr spectroscopy. The correlation method of spectral accumulation provided pmr spectra of good resolution, and in addition the signal-...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00673a032
更新日期:1975-01-28 00:00:00
abstract::Pantothenate synthetase (PS, EC 6.3.2.1) is the last enzyme in the pantothenate biosynthesis pathway, a metabolic pathway identified as a potential target for new antimicrobials. PS catalyzes the ATP-dependent condensation of pantoate and beta-alanine to form pantothenate. Here we report the overexpression, purificati...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi1004206
更新日期:2010-08-03 00:00:00
abstract::Coordinate regulation of PARP-1 and -2 and PARG is required for cellular responses to genotoxic stress. While PARP-1 and -2 are regulated by DNA breaks and covalent modifications, mechanisms of PARG regulation are poorly understood. We report here discovery of a PARG regulatory segment far removed linearly from residu...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi100973m
更新日期:2010-09-07 00:00:00
abstract::The generation of neutralizing antibodies by peptide immunization is dependent on achieving conformational compatibility between antibodies and native protein. Consequently, approaches are needed for developing conformational mimics of protein neutralization sites. We replace putative main-chain hydrogen bonds (NH -->...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0003691
更新日期:2000-11-28 00:00:00
abstract::We describe an assay for detecting intramolecular triple-stranded DNA in living cells. The assay involves quantitative analysis of the differential photobinding of 4,5',8-trimethylpsoralen to 5'TA and 5'AT dinucleotides in a region of plasmid DNA containing the triplex-forming sequence (GA)7TA(GA)7. Psoralen photobind...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00075a013
更新日期:1993-06-22 00:00:00
abstract::A core Y61F mutant of the gene 5 single-stranded DNA-binding protein (g5p) of f1 bacterial virus aggregated when expressed from a plasmid, but, after refolding in vitro, it behaved much like wild-type and may be a stability or folding mutant. Circular dichroism (CD) titrations showed the same cooperative polynucleotid...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi972545k
更新日期:1998-05-19 00:00:00
abstract::A T203Y substitution in green fluorescent protein causes a red shift in emission to yield a class of mutants known as yellow fluorescent protein (YFP). Many of these YFP mutants bind halides with affinities in the millimolar range, which often results in the chromophore pK values being shifted into the physiological r...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi3016839
更新日期:2013-04-09 00:00:00
abstract::Quinone oxidoreductase 2 (QR2) purified from human red blood cells was recently shown to be a potential target of the quinoline antimalarial compounds [Graves et al., (2002) Mol. Pharmacol. 62, 1364]. QR2 catalyzes the two-electron reduction of menadione via the oxidation of N-alkylated or N-ribosylated nicotinamides....
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi035923w
更新日期:2004-04-20 00:00:00
abstract::The structure of the dimeric form of the protein L7/L12 from ribosomes from Escherichia coli was studied by using the heterobifunctional cross-linker 4-(6-formyl-3-azidophenoxy)butyrimidate. The imidate group of the cross-linker reacts very specifically with Lys-51 of L7/L12. Subsequent cross-linking of this modified ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00507a057
更新日期:1981-02-17 00:00:00
abstract::Escherichia coli alkaline phosphatase (AP) is the prototypical two metal ion catalyst with two divalent zinc ions bound approximately 4 A apart in the active site. Studies spanning half a century have elucidated many structural and mechanistic features of this enzyme, rendering it an attractive model for investigating...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi012166y
更新日期:2002-03-05 00:00:00
abstract::Antifreeze proteins (AFPs) inhibit the growth of ice by binding to the surface of ice crystals, preventing the addition of water molecules to cause a local depression of the freezing point. AFPs from insects are much more effective at depressing the freezing point than fish AFPs. Here, we have investigated the possibi...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi035605x
更新日期:2004-01-13 00:00:00
abstract::Extended hydrogen bond networks are a common structural motif of enzymes. A recent analysis proposed quantum delocalization of protons as a feature present in the hydrogen bond network spanning a triad of tyrosines (Y(16), Y(32), and Y(57)) in the active site of ketosteroid isomerase (KSI), contributing to its unusual...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.5b00958
更新日期:2015-12-08 00:00:00
abstract::The spin equilibria of several derivatives of human methemoglobin were probed by resonance Raman scattering. The intensity of lines in the Raman spectrum gives a measure of the high-spin (S = 5/2) to low-spin (S = 1/2) ratio which agrees well with the spin equilibria determined from direct magnetic susceptibility meas...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00438a056
更新日期:1989-06-13 00:00:00
abstract::Tissue factor pathway inhibitor (TFPI) from different cell lines shows up to 15-fold differences in the ratio of anticoagulant to chromogenic activity. The anticoagulant activity was dependent on the purification procedure used and it was possible to isolate two fractions of recombinant TFPI. Only one of these fractio...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00107a002
更新日期:1991-10-29 00:00:00
abstract::We have investigated the denaturation by guanidine hydrochloride (Gdn X HCl), temperature, and pH of hemoglobin beta subunits and of the peptides beta (1-146), beta (56-146), and beta (1-55). The last peptide was insensitive to all of the three agents. In the other polypeptides denaturation by Gdn X HCl and temperatur...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00267a024
更新日期:1982-11-23 00:00:00
abstract::A study of the regular secondary structure elements of recombinant human interleukin-1 beta has been carried out using NMR spectroscopy. Using a randomly 15N labeled sample, a number of heteronuclear three- and two-dimensional NMR experiments have been performed, which have enabled a complete analysis of short-, mediu...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00471a023
更新日期:1990-05-15 00:00:00
abstract::The presence of a N-(2-deoxy-D-erythro pentofuranosyl)urea (henceforth referred to as deoxyribosylurea) residue, ring fragmentation product of a thymine, in a frameshift situation in the sequence 5'd(AGGACCACG).d(CGTGGurTCCT) has been studied by 1H and 31P nuclear magnetic resonance and molecular dynamics. At equilibr...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi971202j
更新日期:1998-01-27 00:00:00
abstract::Understanding the evolution of allostery in multidomain enzymes remains an important step in improving our ability to identify and exploit structure-function relationships in allosteric mechanisms. A recent protein similarity network for the DRE-TIM metallolyase superfamily indicated there are two evolutionarily disti...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi500702u
更新日期:2014-07-29 00:00:00
abstract::4-Oxalocrotonate tautomerase (4-OT) and YwhB, a 4-OT homologue found in Bacillus subtilis, exhibit a low level hydratase activity that converts trans-3-haloacrylates to acetaldehyde, presumably through a malonate semialdehyde intermediate. The mechanism for the initial transformation of the 3-haloacrylate to malonate ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi035495u
更新日期:2004-01-27 00:00:00
abstract::Tombusviruses use a 19 kDa protein (p19) as a suppressor of the RNA silencing pathway during infection. The p19 protein binds to short-interfering RNA (siRNA) as a dimer and shows a high selectivity for short duplex RNAs over other RNA species. Since p19 can bind to synthetic and RNA silencing generated small RNAs wit...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi800401y
更新日期:2008-08-05 00:00:00
abstract::Double-stranded complementary deoxyribonucleic acid (cDNA) transcribed in vitro from a partially pure myosin light-chain messenger ribonucleic acid (mRNA) of the chick embryonic heart was cloned in Escherichia coli strain chi 1776 by using the HindIII cleavage site in the plasmid pBR322. The insertion of essentially f...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00592a019
更新日期:1979-12-11 00:00:00
abstract::The motion of the ethanolamine head group in unsonicated lipid bilayers above and below the phase transition is studied by means of deuterium and phosphorus magnetic resonance. For this purpose, dipalmitoyl-3-sn-phosphatidylethanolamine is selectively deuterated at the two ethanolamine carbon atoms. The deuterium quad...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00669a001
更新日期:1976-11-30 00:00:00