The Role Of Tyrosine Residues In The Rna N-Glycosidase Activity Of Cinnamomin A-Chain

2003 ◽  
Vol 10 (5) ◽  
pp. 503-509
Author(s):  
Hong Xu ◽  
Wang-Yi Liu
Keyword(s):  
Tyrosine Residues ◽  
Glycosidase Activity ◽  
A Chain

Role of TYR70 in the N-glycosidase activity of neo-trichosanthin

Toxicon ◽  
1999 ◽  
Vol 37 (7) ◽  
pp. 961-972 ◽  
Author(s):  
Li Yan ◽  
Shen Wu ◽  
Hui-Guang Li ◽  
Jian-Hui Li ◽  
R.N.-S Wong ◽  
...  
Keyword(s):  
Glycosidase Activity

PUTRACER: A NOVEL METHOD FOR IDENTIFICATION OF CONTINUOUS-DOMAINS IN MULTI-DOMAIN PROTEINS

2013 ◽  
Vol 11 (01) ◽  
pp. 1340012 ◽  
Author(s):  
SEYED SHAHRIAR ARAB ◽  
MOHAMMADBAGHER PARSA GHARAMALEKI ◽  
ZAIDDODINE PASHANDI ◽  
REZVAN MOBASSERI
Keyword(s):  
Protein Structures ◽  
Three Dimensional ◽  
Accessible Surface Area ◽  
Computer Assisted ◽  
Correct Assignment ◽  
Critical Boundary ◽  
Novel Method ◽  
Accessible Surface ◽  
A Chain

Computer assisted assignment of protein domains is considered as an important issue in structural bioinformatics. The exponential increase in the number of known three dimensional protein structures and the significant role of proteins in biology, medicine and pharmacology illustrate the necessity of a reliable method to automatically detect structural domains as protein units. For this aim, we have developed a program based on the accessible surface area (ASA) and the hydrogen bonds energy in protein backbone (HBE). PUTracer (Protein Unit Tracer) is built on the features of a fast top-down approach to cut a chain into its domains (contiguous domains) with minimal change in ASA as well as HBE. Performance of the program was assessed by a comprehensive benchmark dataset of 124 protein chains, which is based on agreement among experts (e.g. CATH, SCOP) and was expanded to include structures with different types of domain combinations. Equal number of domains and at least 90% agreement in critical boundary accuracy were considered as correct assignment conditions. PUTracer assigned domains correctly in 81.45% of protein chains. Although low critical boundary accuracy in 18.55% of protein chains leads to the incorrect assignments, adjusting the scales causes to improve the performance up to 89.5%. We discuss here the success or failure of adjusting the scales with provided evidences. Availability: PUTracer is available at http://bioinf.modares.ac.ir/software/PUTracer/

scholarly journals Insights into the role of protein molecule size and structure on interfacial properties using designed sequences

2013 ◽  
Vol 10 (80) ◽  
pp. 20120987 ◽  
Author(s):  
Mirjana Dimitrijev Dwyer ◽  
Lizhong He ◽  
Michael James ◽  
Andrew Nelson ◽  
Anton P. J. Middelberg
Keyword(s):  
Stress Response ◽  
Molecular Size ◽  
Interfacial Properties ◽  
Protein Molecule ◽  
Mixed System ◽  
Free Energy Of Adsorption ◽  
Air Water Interface ◽  
A Chain ◽  
Size And Structure

Mixtures of a large, structured protein with a smaller, unstructured component are inherently complex and hard to characterize at interfaces, leading to difficulties in understanding their interfacial behaviours and, therefore, formulation optimization. Here, we investigated interfacial properties of such a mixed system. Simplicity was achieved using designed sequences in which chemical differences had been eliminated to isolate the effect of molecular size and structure, namely a short unstructured peptide (DAMP1) and its longer structured protein concatamer (DAMP4). Interfacial tension measurements suggested that the size and bulk structuring of the larger molecule led to much slower adsorption kinetics. Neutron reflectometry at equilibrium revealed that both molecules adsorbed as a monolayer to the air–water interface (indicating unfolding of DAMP4 to give a chain of four connected DAMP1 molecules), with a concentration ratio equal to that in the bulk. This suggests the overall free energy of adsorption is equal despite differences in size and bulk structure. At small interfacial extensional strains, only molecule packing influenced the stress response. At larger strains, the effect of size became apparent, with DAMP4 registering a higher stress response and interfacial elasticity. When both components were present at the interface, most stress-dissipating movement was achieved by DAMP1. This work thus provides insights into the role of proteins' molecular size and structure on their interfacial properties, and the designed sequences introduced here can serve as effective tools for interfacial studies of proteins and polymers.

Role of two adjacent cytoplasmic tyrosine residues in MRP1 (ABCC1) transport activity and sensitivity to sulfonylureas

2005 ◽  
Vol 69 (3) ◽  
pp. 451-461 ◽  
Author(s):  
Gwenaëlle Conseil ◽  
Roger G. Deeley ◽  
Susan P.C. Cole
Keyword(s):  
Transport Activity ◽  
Tyrosine Residues

Migration of protons in a chain of tyrosine residues

2001 ◽  
Vol 84 (4) ◽  
pp. 409-415 ◽  
Author(s):  
V. E. Stefanov ◽  
A. A. Tulub
Keyword(s):  
Tyrosine Residues ◽  
A Chain

Rôle du mésoderme somitique dans le développement du plumage dorsal chez l'embryon de Poulet

Development ◽  
1972 ◽  
Vol 28 (2) ◽  
pp. 343-366
Author(s):  
Par Annick Mauger
Keyword(s):  
Early Stage ◽  
Cervical Region ◽  
Lumbar Region ◽  
Chick Embryos ◽  
A Chain ◽  
Normal Differentiation ◽  
Time Of Operation ◽  
Somitic Mesoderm ◽  
Axial Organs

The role of somitic mesoderm in the development of dorsal plumage in chick embryos. II. Regionalisation. Transplantation and inversion experiments were performed on the somitic mesoderm of 2- to 2·5-day chick embryos in order to study the role of regional and axial determinations in the development of the dorsal plumage. The transposition of a piece of somitic mesoderm from the posterior cervical region (where the spinal pteryla is narrow) to the thoraco-lumbar region (where it is wide) leads to a local and unilateral narrowing of the spinal pteryla at the operation site. Conversely, the transposition of somitic mesoderm from the thoraco-lumbar region to the posterior cervical region results in a local and unilateral widening of the spinal pteryla. Consequently at the time of operation the segmented or not yet segmented somitic mesoderm is already determined to give rise to a definite transverse level of the spinal pteryla. The inversion of the cephalo-caudal polarity of a piece of somitic mesoderm without the ectodermal covering, or of a portion of the axial organs deprived of the overlying ectoderm has no effect on the orientation of feather filaments and feather rows. In contrast, the inversion of the cephalo-caudal polarity of a portion of the axial organs together with the overlying ectoderm results in the development of feathers growing in a cephalad direction and feather chevrons opening towards the head of the embryo. The inversion of the dorso-ventral polarity of a piece of somitic mesoderm does not prevent the normal differentiation of feathers in the operated region. The inversion of the medio-lateral polarity of a piece of unsegmented somitic mesoderm has little effect on the development of the spinal pteryla. On the contrary, the medio-lateral inversion of a chain of somites precludes the formation of the feathers at the level of operation. The somitic mesoderm, even when segmented, is endowed with extensive regulative capacity of its axes, except for the medio-lateral polarity, which is fixed irreversibly at the time of segmentation. The regional determination of the feather-forming somitic mesoderm is acquired at an early stage, at any rate before segmentation. However, at a given transverse level of the cephalo-caudal axis, the somitic cells remain totipotent as concerns their histo-genetic destiny (dermatome, myotome, or sclerotome) until after the onset of segmentation.

Role of arginine 180 and glutamic acid 177 of ricin toxin A chain in enzymatic inactivation of ribosomes

1990 ◽  
Vol 10 (12) ◽  
pp. 6257-6263
Author(s):  
A Frankel ◽  
P Welsh ◽  
J Richardson ◽  
J D Robertus
Keyword(s):  
Enzyme Activity ◽  
Glutamic Acid ◽  
Structural Information ◽  
Wild Type ◽  
Toxin A ◽  
Mutant Proteins ◽  
Ricin Toxin ◽  
Enzymatic Inactivation ◽  
A Chain

The gene for ricin toxin A chain was modified by site-specific mutagenesis to change arginine 180 to alanine, glutamine, methionine, lysine, or histidine. Separately, glutamic acid 177 was changed to alanine and glutamic acid 208 was changed to aspartic acid. Both the wild-type and mutant proteins were expressed in Escherichia coli and, when soluble, purified and tested quantitatively for enzyme activity. A positive charge at position 180 was found necessary for solubility of the protein and for enzyme activity. Similarly, a negative charge with a proper geometry in the vicinity of position 177 was critical for ricin toxin A chain catalysis. When glutamic acid 177 was converted to alanine, nearby glutamic acid 208 could largely substitute for it. This observation provided valuable structural information concerning the nature of second-site mutations.

scholarly journals Phosphorylation of the overlooked tyrosine 310 regulates the structure, aggregation, and microtubule- and lipid-binding properties of Tau

2020 ◽  
Vol 295 (23) ◽  
pp. 7905-7922 ◽  
Author(s):  
Nadine Ait-Bouziad ◽  
Anass Chiki ◽  
Galina Limorenko ◽  
Shifeng Xiao ◽  
David Eliezer ◽  
...  
Keyword(s):  
Lipid Binding ◽  
Binding Properties ◽  
Post Translational Modifications ◽  
Unique Role ◽  
Tyrosine Residues ◽  
Normal Functions ◽  
Tau Aggregation ◽  
Β Sheet

The microtubule-associated protein Tau is implicated in the pathogenesis of several neurodegenerative disorders, including Alzheimer's disease. Increasing evidence suggests that post-translational modifications play critical roles in regulating Tau's normal functions and its pathogenic properties in tauopathies. Very little is known about how phosphorylation of tyrosine residues influences the structure, aggregation, and microtubule- and lipid-binding properties of Tau. Here, we sought to determine the relative contributions of phosphorylation of one or several of the five tyrosine residues in Tau (Tyr-18, -29, -197, -310, and -394) to the regulation of its biophysical, aggregation, and functional properties. We used a combination of site-specific mutagenesis and in vitro phosphorylation by c-Abl kinase to generate Tau species phosphorylated at all five tyrosine residues, all tyrosine residues except Tyr-310 or Tyr-394 (pTau-Y310F and pTau-Y394F, respectively) and Tau phosphorylated only at Tyr-310 or Tyr-394 (4F/pTyr-310 or 4F/pTyr-394). We observed that phosphorylation of all five tyrosine residues, multiple N-terminal tyrosine residues (Tyr-18, -29, and -197), or specific phosphorylation only at residue Tyr-310 abolishes Tau aggregation and inhibits its microtubule- and lipid-binding properties. NMR experiments indicated that these effects are mediated by a local decrease in β-sheet propensity of Tau's PHF6 domain. Our findings underscore Tyr-310 phosphorylation has a unique role in the regulation of Tau aggregation, microtubule, and lipid interactions. These results also highlight the importance of conducting further studies to elucidate the role of Tyr-310 in the regulation of Tau's normal functions and pathogenic properties.

The role of tissue-type plasminogen activator A-chain domains in plasma clearance

1989 ◽  
Vol 3 (4) ◽  
pp. 207-214 ◽  
Author(s):  
M.J. Browne ◽  
C.G. Chapman ◽  
I. Dodd ◽  
B. Reavy ◽  
A.F. Esmail ◽  
...  
Keyword(s):  
Plasminogen Activator ◽  
Plasma Clearance ◽  
Tissue Type ◽  
Tissue Type Plasminogen Activator ◽  
Type Plasminogen Activator ◽  
A Chain
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