Abstract:
:We have examined the affinity of two recently synthesized flavin analogs for the isoalloxazine binding site of riboflavin-binding protein (RBP). The results showed that pyrimidopteridines could bind to RBP (Kd 160-250 microM). This suggested that, at the FMN or FAD level, these analogs might also bind to other apoflavoproteins, thereby providing a high potential probe for flavin enzymology. In contrast, 4a,5-ring-opened isoalloxazines did not bind to RBP. However, 1,10a-ring-opened flavins bind with considerable avidity (Kd about 40 nM). Evidence is presented which indicates that the 4a,5-ring-opened species adopted a nonplanar configuration which, in turn, was responsible for the lack of affinity to RBP. Steric and electronic consequences of a 4a,5 ring opening are discussed in relation to flavin-dependent phenolic hydroxylases.
journal_name
Proc Natl Acad Sci U S Aauthors
Wessiak A,Schopfer LM,Yuan LC,Bruice TC,Massey Vdoi
10.1073/pnas.81.14.4246subject
Has Abstractpub_date
1984-07-01 00:00:00pages
4246-9issue
14eissn
0027-8424issn
1091-6490journal_volume
81pub_type
杂志文章abstract::GLQ223 is a highly purified, formulated preparation of trichosanthin, a 26-kDa plant-derived ribosome-inactivating protein with potent inhibitory activity against human immunodeficiency virus (HIV) in vitro. The compound produced concentration-dependent inhibition of HIV replication in acutely infected cultures of T-l...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.86.8.2844
更新日期:1989-04-01 00:00:00
abstract::Knowledge of the relative contributions of different water sources to intracellular fluids and body water is important for many fields of study, ranging from animal physiology to paleoclimate. The intracellular fluid environment of cells is challenging to study due to the difficulties of accessing and sampling the con...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1521038113
更新日期:2016-05-24 00:00:00
abstract::The transcription factor caudal-type homeobox 1 (CDX1) is a key regulator of differentiation in the normal colon and in colorectal cancer (CRC). CDX1 activates the expression of enterocyte genes, but it is not clear how the concomitant silencing of stem cell genes is achieved. MicroRNAs (miRNAs) are important mediator...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1503370112
更新日期:2015-03-31 00:00:00
abstract::Drug resistance testing has been shown to be beneficial for clinical management of HIV type 1 infected patients. Whereas phenotypic assays directly measure drug resistance, the commonly used genotypic assays provide only indirect evidence of drug resistance, the major challenge being the interpretation of the sequence...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.112177799
更新日期:2002-06-11 00:00:00
abstract::Agrobacterium tumefaciens causes crown gall tumors on various plants by delivering transferred DNA (T-DNA) and virulence proteins into host plant cells. Under laboratory conditions, the bacterium is widely used as a vector to genetically modify a wide range of organisms, including plants, yeasts, fungi, and algae. Var...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1612098114
更新日期:2017-03-14 00:00:00
abstract::We recently showed that culture-derived metacyclic trypomastigotes (CMT), but not epimastigotes (Epi), of the Miranda 88 strain of Trypanosoma cruzi evade lysis by the human alternative complement pathway because of inefficient binding of factor B to complement component C3b on the parasite surface. These results sugg...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.85.1.193
更新日期:1988-01-01 00:00:00
abstract::The term amyloid defines a group of proteins that aggregate into plaques or fibers. Amyloid fibers gained their fame mostly due to their relation with neurodegenerative diseases in humans. However, secreted by lower organisms, such as bacteria and fungi, amyloid fibers play a functional role: for example, when they se...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1908782116
更新日期:2019-11-05 00:00:00
abstract::Variation between North Korean and Latin American isolates in the circumsporozoite (CS) protein encoding gene of the human malaria parasite Plasmodium vivax was studied. Polymorphic positions are confined to the central tandemly repeated sequences. Nucleotide substitutions in the tandem repeats produce variants; these...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.85.21.8102
更新日期:1988-11-01 00:00:00
abstract::The probability of choosing an alternative in a long sequence of repeated choices is proportional to the total reward derived from that alternative, a phenomenon known as Herrnstein's matching law. This behavior is remarkably conserved across species and experimental conditions, but its underlying neural mechanisms st...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0505220103
更新日期:2006-10-10 00:00:00
abstract::Ca(2+) signaling regulates cell function. This is subject to modulation by H(+) ions that are universal end-products of metabolism. Due to slow diffusion and common buffers, changes in cytoplasmic [Ca(2+)] ([Ca(2+)]i) or [H(+)] ([H(+)]i) can become compartmentalized, leading potentially to complex spatial Ca(2+)/H(+) ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1222433110
更新日期:2013-05-28 00:00:00
abstract::A transformation-defective mutant of Abelson murine leukemia virus (A-MuLV), called A-MuLV-P92td, has been isolated. The mutant encodes a serologically identifiable A-MuLV protein of molecular weight 92,000 (P92) but it lacks the ability to transform either fibroblasts or bone marrow lymphoid cells. In contrast to the...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.77.8.4993
更新日期:1980-08-01 00:00:00
abstract::Expression of the Arabidopsis TRANSPARENT TESTA 2 (TT2) MYB family transcription factor leads to massive accumulation of proanthocyanidins (PAs) in hairy roots of Medicago truncatula. Microarray analysis showed that TT2 induces genes for flavonoid/PA biosynthesis, transcription factors, and a large number of genes of ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0805954105
更新日期:2008-09-16 00:00:00
abstract::The completion of the human genome project and the development of high-throughput approaches herald a dramatic acceleration in the pace of biological research. One of the most compelling next steps will be learning the functional roles of all proteins. Achievement of this goal depends in part on the rapid expression a...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.042684199
更新日期:2002-03-05 00:00:00
abstract::Monoclonal antibodies were used to isolate nonneutralizable antigenic variants in the hemagglutinin-neuraminidase glycoprotein of Newcastle disease virus. It had been found that a large percentage of virus retains infectivity despite binding neutralizing antibody. This high persistent fraction of nonneutralized virus ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.82.20.7106
更新日期:1985-10-01 00:00:00
abstract::Cytochrome P450IIC5 (rabbit liver 21-hydroxylase) is unusual among hepatic forms of cytochromes P450 because it catalyzes the conversion of one active steroid hormone (progesterone) to another active hormone (deoxycorticosterone). Another interesting aspect of this steroid-hydroxylating enzyme is the ability to conver...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.87.24.9756
更新日期:1990-12-01 00:00:00
abstract::Cry proteins produced by Bacillus thuringiensis are selective biodegradable insecticides used increasingly in bacterial insecticides and transgenic plants as alternatives to synthetic chemical insecticides. However, the potential for development of resistance and cross-resistance in target insect populations to Cry pr...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.94.20.10536
更新日期:1997-09-30 00:00:00
abstract::Syringomycin, a peptide toxin and a virulence factor produced by the bacterial phytopathogen Pseudomonas syringae pv. syringae, stimulated the phosphorylation of several plasma membrane polypeptides of red beet storage tissue. Among these was a 100-kDa polypeptide, which corresponds in size to the proton pump ATPase. ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.84.19.6755
更新日期:1987-10-01 00:00:00
abstract::Structural protein 4.1, which has crucial interactions within the spectrin-actin lattice of the human red cell membrane skeleton, also is widely distributed at diverse intracellular sites in nucleated cells. We previously showed that 4.1 is essential for assembly of functional nuclei in vitro and that the capacity of ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1934680100
更新日期:2003-09-16 00:00:00
abstract::The MAL6 locus is one of five closely related unlinked loci, any one of which is sufficient for fermentation of maltose in Saccharomyces. Previous genetic analysis indicated that this locus is defined by two complementation groups, MALp and MALg. MALp reportedly is a regulatory gene required for inducible synthesis of...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.81.9.2811
更新日期:1984-05-01 00:00:00
abstract::Four overlapping cosmid clones were constructed that contain the complete genome of the attenuated Oka strain of VZV. Transfection of human melanoma cells with the four cosmids resulted in production of infectious VZV. A double-stranded oligonucleotide, encoding a stop codon in all three open reading frames, was inser...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.90.15.7376
更新日期:1993-08-01 00:00:00
abstract::We are interested in using recombinant adeno-associated viral vectors in the treatment of hemophilia A. Because of the size constraints of recombinant adeno-associated viral vectors, we delivered the heavy and light chains of the human factor 8 (hFVIII) cDNA independently by using two separate vectors. Recombinant AAV...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.96.22.12725
更新日期:1999-10-26 00:00:00
abstract::Humans speak, monkeys grunt, and ducks quack. How do we come to know which vocalizations animals produce? Here we explore this question by asking whether young infants expect humans, but not other animals, to produce speech, and further, whether infants have similarly restricted expectations about the sources of vocal...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0906049106
更新日期:2009-11-03 00:00:00
abstract::Hereditary deficiency of factor IXa (fIXa), a key enzyme in blood coagulation, causes hemophilia B, a severe X chromosome-linked bleeding disorder afflicting 1 in 30,000 males; clinical studies have identified nearly 500 deleterious variants. The x-ray structure of porcine fIXa described here shows the atomic origins ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.92.21.9796
更新日期:1995-10-10 00:00:00
abstract::Advances in vaccine technology over the past two centuries have facilitated far-reaching impact in the control of many infections, and today's emerging vaccines could likewise open new opportunities in the control of several diseases. Here we consider the potential, population-level effects of a particular class of em...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1209683109
更新日期:2012-12-04 00:00:00
abstract::The first definitive/adult-type hematopoietic stem cells (HSCs) in the mouse aorta-gonad-mesonephros region emerge between embryonic days 10.5 and 11.5. The discovery of clusters of hematopoietic cells on the ventral luminal surface of the dorsal aorta in various vertebrate species has led to speculation that the floo...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0700984104
更新日期:2007-05-29 00:00:00
abstract::Bacteriophage 434 encodes a repressor that, like bacteriophage lambda repressor, both activates and represses transcription. As in the lambda chromosome, a region of the 434 chromosome, called the right operator, contains three repressor binding sites (OR1, OR2, and OR3) that mediate these effects on two adjacent prom...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.83.24.9353
更新日期:1986-12-01 00:00:00
abstract::Yawn contagion in humans has been proposed to be related to our capacity for empathy. It is presently unclear whether this capacity is uniquely human or shared with other primates, especially monkeys. Here, we show that in gelada baboons (Theropithecus gelada) yawning is contagious between individuals, especially thos...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0910891106
更新日期:2009-11-17 00:00:00
abstract::We have reexamined the balance between cell birth, cell maturation, and cell death in the thymus by labeling dividing thymocytes and their progeny in vivo with [3H]-thymidine, isolating clearly defined subpopulations by fluorescence-activated cell sorting, and determining the distribution of label by autoradiography. ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.87.7.2579
更新日期:1990-04-01 00:00:00
abstract::For almost a century, alcohols have been thought to produce their effects by actions on the membrane lipids of central nervous system neurons--the well known "lipid theory" of alcohol action. The rationale for this theory is the correlation of potency with oil/water or membrane/buffer partition coefficient. Although a...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.91.17.8200
更新日期:1994-08-16 00:00:00
abstract::The outer membrane (OM) of Gram-negative bacteria forms a robust permeability barrier that blocks entry of toxins and antibiotics. Most OM proteins (OMPs) assume a β-barrel fold, and some form aqueous channels for nutrient uptake and efflux of intracellular toxins. The Bam machine catalyzes rapid folding and assembly ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1806107115
更新日期:2018-07-10 00:00:00