scholarly journals G‐Quadruplexes act as sequence‐dependent protein chaperones

EMBO Reports ◽  
2020 ◽  
Vol 21 (10) ◽  
Author(s):  
Adam Begeman ◽  
Ahyun Son ◽  
Theodore J Litberg ◽  
Tadeusz H Wroblewski ◽  
Thane Gehring ◽  
...  
Keyword(s):  
Sequence Dependent ◽  
Protein Chaperones ◽  
Dependent Protein

scholarly journals A Model of Sequence-Dependent Protein Diffusion Along DNA

2004 ◽  
Vol 30 (3) ◽  
pp. 203-226 ◽  
Author(s):  
Maria Barbi ◽  
Christophe Place ◽  
Vladislav Popkov ◽  
Mario Salerno
Keyword(s):  
Protein Diffusion ◽  
Sequence Dependent ◽  
Dependent Protein

SDRL: a sequence-dependent protein side-chain rotamer library

2015 ◽  
Vol 11 (7) ◽  
pp. 2000-2007 ◽  
Author(s):  
Mohammad Taghizadeh ◽  
Bahram Goliaei ◽  
Armin Madadkar-Sobhani
Keyword(s):  
Amino Acid ◽  
Side Chain ◽  
Side Chains ◽  
Rotamer Library ◽  
Conformational Selection ◽  
Sequence Dependent ◽  
Amino Acid Side Chains ◽  
Dependent Protein ◽  
Selection Of

We established a sequence-dependent rotamer library (SDRL) to help in modeling side chains, better understanding of the conformational selection of amino acid side chains and the search for the neighbor dependency of this conformational selection.

scholarly journals Constructing sequence-dependent protein models using coevolutionary information

2015 ◽  
Vol 25 (1) ◽  
pp. 111-122 ◽  
Author(s):  
Ryan R. Cheng ◽  
Mohit Raghunathan ◽  
Jeffrey K. Noel ◽  
José N. Onuchic
Keyword(s):  
Sequence Dependent ◽  
Dependent Protein ◽  
Protein Models

Protein S and C4b-Binding Protein: Components Involved in the Regulation of the Protein C Anticoagulant System

1991 ◽  
Vol 66 (01) ◽  
pp. 049-061 ◽  
Author(s):  
Björn Dahlbäck
Keyword(s):  
Vitamin K ◽  
Complement System ◽  
Protein C ◽  
Protein S ◽  
High Affinity ◽  
Anticoagulant System ◽  
Dependent Protein ◽  
The Complement System ◽  
Β Chain ◽  
Dependent Domain

SummaryThe protein C anticoagulant system provides important control of the blood coagulation cascade. The key protein is protein C, a vitamin K-dependent zymogen which is activated to a serine protease by the thrombin-thrombomodulin complex on endothelial cells. Activated protein C functions by degrading the phospholipid-bound coagulation factors Va and VIIIa. Protein S is a cofactor in these reactions. It is a vitamin K-dependent protein with multiple domains. From the N-terminal it contains a vitamin K-dependent domain, a thrombin-sensitive region, four EGF)epidermal growth factor (EGF)-like domains and a C-terminal region homologous to the androgen binding proteins. Three different types of post-translationally modified amino acid residues are found in protein S, 11 γ-carboxy glutamic acid residues in the vitamin K-dependent domain, a β-hydroxylated aspartic acid in the first EGF-like domain and a β-hydroxylated asparagine in each of the other three EGF-like domains. The EGF-like domains contain very high affinity calcium binding sites, and calcium plays a structural and stabilising role. The importance of the anticoagulant properties of protein S is illustrated by the high incidence of thrombo-embolic events in individuals with heterozygous deficiency. Anticoagulation may not be the sole function of protein S, since both in vivo and in vitro, it forms a high affinity non-covalent complex with one of the regulatory proteins in the complement system, the C4b-binding protein (C4BP). The complexed form of protein S has no APC cofactor function. C4BP is a high molecular weight multimeric protein with a unique octopus-like structure. It is composed of seven identical α-chains and one β-chain. The α-and β-chains are linked by disulphide bridges. The cDNA cloning of the β-chain showed the α- and β-chains to be homologous and of common evolutionary origin. Both subunits are composed of multiple 60 amino acid long repeats (short complement or consensus repeats, SCR) and their genes are located in close proximity on chromosome 1, band 1q32. Available experimental data suggest the β-chain to contain the single protein S binding site on C4BP, whereas each of the α-chains contains a binding site for the complement protein, C4b. As C4BP lacking the β-chain is unable to bind protein S, the β-chain is required for protein S binding, but not for the assembly of the α-chains during biosynthesis. Protein S has a high affinity for negatively charged phospholipid membranes, and is instrumental in binding C4BP to negatively charged phospholipid. This constitutes a novel mechanism for control of the complement system on phospholipid surfaces. Recent findings have shown circulating C4BP to be involved in yet another calcium-dependent protein-protein interaction with a protein known as the serum amyloid P-component (SAP). The binding sites on C4BP for protein S and SAP are independent. SAP, which is a normal constituent in plasma and in tissue, is a so-called pentraxin being composed of 5 non-covalently bound 25 kDa subunits. It is homologous to C reactive protein (CRP) but its function is not yet known. The specific high affinity interactions between protein S, C4BP and SAP suggest the regulation of blood coagulation and that of the complement system to be closely linked.

Molecular Forms of Human Protein C: Comparison and Distribution in Human Adult Plasma

1989 ◽  
Vol 62 (03) ◽  
pp. 902-905 ◽  
Author(s):  
Brian S Greffe ◽  
Marilyn J Manco-Johnson ◽  
Richard A Marlar
Keyword(s):  
Heavy Chain ◽  
Protein C ◽  
Molecular Forms ◽  
Post Translational Modification ◽  
Single Chain ◽  
Beta Form ◽  
Sds Page ◽  
Dependent Protein ◽  
Adult Plasma ◽  
The Difference

SummaryProtein C (PC) is a vitamin K-dependent protein which functions as both an anticoagulant and profibrinolytic. It is synthesized as a single chain protein (SC-PC) and post-transla-tionally modified into a two chain form (2C-PC). Two chain PC consists of a light chain (LC) and a heavy chain (HC). The present study was undertaken to determine the composition of the molecular forms of PC in plasma. PC was immunoprecipitated, subjected to SDS-PAGE and Western blotting. The blots were scanned by densitometry to determine the distribution of the various forms. The percentage of SC-PC and 2C-PC was found to be 10% and 90% respectively. This is in agreement with previous work. SC-PC and the heavy chain of 2C-PC consisted of three molecular forms (“alpha”, “beta”, and “gamma”). The “alpha” form of HC is the standard 2C form with a MW of 40 Kd. The “beta” form of HC has also been described and has MW which is 4 Kd less than the “alpha” form. The “gamma” species of the SC and 2C-PC has not been previously described. However, its 3 Kd difference from the “beta” form could be due to modification of the “beta” species or to a separate modification of the alpha-HC. The LC of PC was shown to exist in two forms (termed form 1 and form 2). The difference between these two forms is unknown. The molecular forms of PC are most likely due to a post-translational modification (either loss of a carbohydrate or a peptide) rather than from plasma derived degradation.

Sign in / Sign up

Export Citation Format

Share Document