Abstract:
:Papain-solubilized human class II (HLA-DR) antigens have been purified from cadaveric spleens by ion-exchange chromatography, gel chromatography, and immunosorbent purification. The isolated papain-solubilized antigens comprised two subunits with apparent molecular weights of 23 000 and 30 000, respectively. The circular dichroism spectrum for the isolated class II antigens was similar to spectra recorded for HLA-A, -B, and -C antigens, immunoglobulins, and immunoglobulin fragments. Thus, class II antigens contain a considerable amount of beta structure. The small subunit (beta chain) exhibited extensive charge heterogeneity on two-dimensional isoelectric focusing polyacrylamide gel electrophoresis, whereas the large subunit (alpha chain) was more homogeneous. The structural heterogeneity of beta chains remained after neuraminidase treatment. The NH2-terminal amino acid sequence of the beta chains displayed multiple residues in several positions in accordance with the genetic polymorphism displayed by this chain. The alpha chain also displayed multiple residues in some positions, suggesting either that some of the genetic polymorphism of the class II antigens may be endowed in this chain or that multiple loci control the expression of several alpha chains. Papain-solubilized class II antigen subunits were homologous in their amino acid sequences with HLA-DR antigens of defined antigenic specificity as well as with murine I-E/C antigens.
journal_name
Biochemistryjournal_title
Biochemistryauthors
Wiman K,Claesson L,Rask L,Trägårdh L,Peterson PAdoi
10.1021/bi00264a036subject
Has Abstractpub_date
1982-10-12 00:00:00pages
5351-8issue
21eissn
0006-2960issn
1520-4995journal_volume
21pub_type
杂志文章相关文献
BIOCHEMISTRY文献大全abstract::The effects of Ca2+, Mg2+, and troponin I (TnI) inhibitory peptide (Ip) binding on the spectral properties of a Phe-154 to Trp mutant (F154W) of chicken recombinant troponin C (rTnC) have been examined. Residue 154 is positioned in the final flanking helix H of metal binding site IV. Since there are no other Tyr or Tr...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00176a028
更新日期:1994-03-15 00:00:00
abstract::N-Ethylmaleimide (NEM), which reacts readily with exposed sulfhydryl groups, has been shown to inhibit the activity of the microtubule (MT) motors kinesin, Ncd, and dynein. Currently, the mechanism of inhibition is not known for any of these proteins. To investigate the mechanism by which NEM inhibits Ncd, the recombi...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi990706+
更新日期:1999-08-17 00:00:00
abstract::We have found a correlation between liposome fusion kinetics and lipid phase behavior for several inverted phase forming lipids. N-Methylated dioleoylphosphatidylethanolamine (DOPE-Me), or mixtures of dioleoylphosphatidylethanolamine (DOPE) and dioleoylphosphatidylcholine (DOPC), will form an inverted hexagonal phase ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00435a011
更新日期:1989-05-02 00:00:00
abstract::Folding experiments have suggested that some proteins have kinetic intermediates with a non-native structure. A simple G ̅o model does not explain such non-native intermediates. Therefore, the folding energy landscape of proteins with non-native intermediates should have characteristic properties. To identify such pro...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi200241a
更新日期:2011-07-26 00:00:00
abstract::Beta-lactamases are the most widespread resistance mechanism to beta-lactam antibiotics, such as the penicillins and cephalosporins. Transition-state analogues that bind to the enzymes with nanomolar affinities have been introduced in an effort to reverse the resistance conferred by these enzymes. To understand the or...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi035054a
更新日期:2003-12-16 00:00:00
abstract::The kinetic and equilibrium CO binding properties of hemoglobin (Hb) M Iwate (alpha2 87 His leads to Tyr beta2) have been investigated. The results show that the alpha(Met) beta2 (CO) tetramer of this protein has a low affinity for CO, as indicated by the stopped-flow and flash-photolysis kinetic, as well as the CO bi...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00669a022
更新日期:1976-11-30 00:00:00
abstract::The crystal structure of a human carbonic anhydrase II (CAII) variant, cis-proline-202-->alanine (P202A), has been determined at 1.7-A resolution, indicating that the wild-type geometry, including the cis-peptidyl linkage, is retained upon substitution of proline by alanine. The CO2 hydrase activity and affinity for s...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00092a003
更新日期:1993-10-19 00:00:00
abstract::While calcium binding to troponin C (TnC) triggers the contraction of both skeletal and cardiac muscle, there is clear evidence that different mechanisms may be involved. For example, activation of heart myofilaments occurs with binding to a single regulatory site on TnC, whereas activation of fast skeletal myofilamen...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi971223d
更新日期:1997-10-07 00:00:00
abstract::The amino acid composition and sequence of EIIMtl is known [Lee, C. A., & Saier, M. H., Jr. (1983) J. Biol. Chem. 258, 10761-10767]. This information was combined, in the present study, with quantitative amino acid analysis to determine the molar concentration of the enzyme. The stoichiometry of phosphoryl group incor...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00415a020
更新日期:1988-07-26 00:00:00
abstract::The guanyl nucleotide binding regulatory protein of retinal rod outer segments, called Gt, that couples the photon receptor rhodopsin with the light-activated cGMP phosphodiesterase, can be resolved into two functional components, alpha t and beta gamma t. The effect of monoclonal antibody binding to the alpha t subun...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00451a047
更新日期:1989-12-12 00:00:00
abstract::R67 dihydrofolate reductase (DHFR), which catalyzes the NADPH dependent reduction of dihydrofolate to tetrahydrofolate, belongs to a type II family of R-plasmid encoded DHFRs that confer resistance to the antibacterial drug trimethoprim. Crystal structure data reveals this enzyme is a homotetramer that possesses a sin...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi034643d
更新日期:2003-09-16 00:00:00
abstract::Photochemical and subsequent thermal reactions of rhodopsin containing 9-cis-retinal [Rh(9)] or one of four analogues with 9-cis geometries formed from ring-modified retinals, alpha-retinal [alpha Rh(9)], acyclic retinal [AcRh(9)], acyclic alpha-retinal [Ac alpha Rh(9)], and 5-isopropyl-alpha-retinal [P alpha Rh(9)] w...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00233a022
更新日期:1991-05-14 00:00:00
abstract::An expression plasmid encoding the extracellular portion of the human tumor necrosis factor (TNF) type 1 receptor (TNF-R1) was constructed and used to generate a stable cell line secreting soluble TNF-R1 (sTNF-R1). The sTNF-R1 was purified, and its biochemical properties and its interactions with human TNF-alpha were ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00119a023
更新日期:1992-02-04 00:00:00
abstract::The crystal structure and spectroscopic properties of the periplasmic penta-heme cytochrome c nitrite reductase (NrfA) of Escherichia coli are presented. The structure is the first for a member of the NrfA subgroup that utilize a soluble penta-heme cytochrome, NrfB, as a redox partner. Comparison to the structures of ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi015765d
更新日期:2002-03-05 00:00:00
abstract::To develop molecules capable of directly probing the catechol binding region of the beta(2)-adrenergic receptor (beta(2)AR), novel benzophenone- and fluorenone-based beta(2)AR antagonists were prepared as potential photoaffinity probes. While the benzophenone-containing ligands bound with relatively modest affinity, o...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi001342k
更新日期:2000-10-24 00:00:00
abstract::Ultraviolet resonance Raman (RR) spectra, with 200- and 218-nm excitation from a H2-shifted quadrupled Nd:YAG laser, are reported for insulin and alpha-lactalbumin in dilute aqueous solution, at pH values known to produce differences in the exposure of the aromatic residues to solvent. At 200 nm, the spectra are domin...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00329a009
更新日期:1985-04-09 00:00:00
abstract::We investigated the effects of substituting two of the four tryptophans (the "inner pair" Trp(9) and Trp(11) or the "outer pair" Trp(13) and Trp(15)) in gramicidin A (gA) channels. The conformational preferences of the doubly substituted gA analogues were assessed using circular dichroism spectroscopy and size-exclusi...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi200136e
更新日期:2011-06-07 00:00:00
abstract::Cibacron Blue F3GA, the polycyclic blue chromophore of Blue Dextran 2000, inhibits the catalytic subunit of bovine brain protein kinase. The rate of inactivation exhibits a hyperbolic dependence on the dye concentration. This suggests that an enzyme-dye complex forms prior to inactivation. Protein and peptide substrat...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00542a022
更新日期:1980-01-08 00:00:00
abstract::The specificity of trypsin for Arg- and Lys-containing substrates depends upon the presence of Asp189 at the base of the primary binding pocket. The crystal structure of anionic rat trypsin D189S complexed with BPTI reveals that removal of the aspartate side chain permits the binding of a well-ordered acetate ion in a...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00177a016
更新日期:1994-03-22 00:00:00
abstract::One of the most promising approaches to anti-hepatitis C virus drug discovery is the development of inhibitors of the virally encoded protease NS3. This chymotrypsin-like serine protease is essential for the maturation of the viral polyprotein, and processing requires complex formation between NS3 and its cofactor NS4...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi991220w
更新日期:1999-10-19 00:00:00
abstract::Exchangeable imidazole NH proton nuclear magnetic resonance (NMR) signals of the proximal histidine F8, which is directly coordinated to the paramagnetic porphyrin cobalt ion, have been measured for cobalt-substituted deoxyhemoglobins (deoxy-CoHb) and iron-cobalt hybrid hemoglobins, alpha (Co)2 beta (Fe)2 and alpha (F...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00281a019
更新日期:1983-06-07 00:00:00
abstract::The third intracellular loop (IL3) of G protein-coupled receptors (GPCRs) is an important contact domain between GPCRs and their G proteins. Previously, the IL3 of Ste2p, a Saccharomyces cerevisiae GPCR, was suggested to undergo a conformational change upon activation as detected by differential protease susceptibilit...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi200254h
更新日期:2011-08-16 00:00:00
abstract::The crystal structure of the recombinant thiamin diphosphate-dependent E1 component from the Escherichia coli pyruvate dehydrogenase multienzyme complex (PDHc) has been determined at a resolution of 1.85 A. The E. coli PDHc E1 component E1p is a homodimeric enzyme and crystallizes with an intact dimer in an asymmetric...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0118557
更新日期:2002-04-23 00:00:00
abstract::The effect of tropomyosin alone on the binding of myosin subfragment 1 (S-1) to actin was compared to that of troponin-tropomyosin, with and without Ca2+. Over a range of ionic strength and with different ligands (adenyl-5'-yl imidodiphosphate, pyrophosphate, and adenosine 5'-diphosphate), tropomyosin confers slight c...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00280a027
更新日期:1983-05-24 00:00:00
abstract::DNA polymerase delta from calf thymus has been purified to apparent homogeneity by a new procedure which utilizes hydrophobic interaction chromatography with phenyl-Sepharose at an early step to separate most of the calcium-dependent protease activity from DNA polymerase delta and alpha. The purified enzyme migrates a...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00304a003
更新日期:1984-04-24 00:00:00
abstract::The addition of a small peptide can significantly increase the rate at which pepsin cleaves a substrate at pH 4.5. Why? In order to find out, we have determined spectrophotometrically the relative ability of over a dozen peptides to speed the initial rate of disappearance of Phe-Trp-NH2 and Leu-Trp-Met-Arg. Here are s...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00514a029
更新日期:1981-05-26 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::Benzoylformate decarboxylase (BFDC) and pyruvate decarboxylase (PDC) are both thiamin diphosphate-dependent enzymes. The two share a common three-dimensional structure and catalyze a similar chemical reaction, i.e., decarboxylation of 2-keto acids. However, they vary significantly in their substrate utilization patter...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi9008402
更新日期:2009-09-08 00:00:00
abstract::The reaction of cytochrome c oxidase with hydrogen peroxide has been of great value in generating and characterizing oxygenated species of the enzyme that are identical or similar to those formed during turnover of the enzyme with dioxygen. Most previous studies have utilized relatively low peroxide concentrations (mi...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi9916675
更新日期:1999-11-30 00:00:00
abstract::The misfolding of amyloid beta (Aβ) is one of the predominant hallmarks in the pathology of Alzheimer's disease (AD). In this study, we showed that the formation of the Aβ ion channel on the membrane depended on the cholesterol concentration. From a mechanical aspect, we found that cholesterol levels affected the stab...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.9b00968
更新日期:2020-03-03 00:00:00