Mass spectral and hydrolytic determination of amino acid sequences in synaptosomal peptides from calf brain

1983 ◽  
Vol 8 (7) ◽  
pp. 933-941 ◽  
Author(s):  
Kirsi-Marja Marnela ◽  
P. L�hdesm�ki
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequences ◽  
Mass Spectral

A head-activator binding protein is present in hydra in a soluble and a membrane-anchored form

Development ◽  
1999 ◽  
Vol 126 (18) ◽  
pp. 4077-4086 ◽  
Author(s):  
W. Hampe ◽  
J. Urny ◽  
I. Franke ◽  
S.A. Hoffmeister-Ullerich ◽  
D. Herrmann ◽  
...  
Keyword(s):  
Stem Cells ◽  
Amino Acid ◽  
Transmembrane Domain ◽  
Binding Protein ◽  
Amino Acid Sequences ◽  
Secreted Protein ◽  
Specific Antibodies ◽  
Head Activator ◽  
Carboxy Terminal

The neuropeptide head activator plays an important role for proliferation and determination of stem cells in hydra. By affinity chromatography a 200 kDa head-activator binding protein, HAB, was isolated from the multiheaded mutant of Chlorohydra viridissima. Partial amino acid sequences were used to clone the HAB cDNA which coded for a receptor with a unique alignment of extracellular modules, a transmembrane domain, and a short carboxy-terminal cytoplasmic tail. A mammalian HAB homologue with identical alignment of these modules is expressed early in brain development. Specific antibodies revealed the presence of HAB in hydra as a transmembrane receptor, but also as secreted protein, both capable of binding head activator. Secretion of HAB during regeneration and expression in regions of high determination potential hint at a role for HAB in regulating the concentration and range of action of head activator.

Determination of Factor Xa Activity by Means of Chromogenic Substrates Based on the Primary Structure of Prothrombin

1975 ◽  
Author(s):  
L. Aurell ◽  
A. Olausson ◽  
G. Claeson
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Primary Structure ◽  
Serine Proteases ◽  
Factor Xa ◽  
Amino Acid Sequences ◽  
Peptide Substrate ◽  
Chromogenic Substrates ◽  
Special Regard

Through the work of Magnusson and co-workers leading to the elucidation of the primary structure of prothrombin including the amino acid sequences around the two bonds split by factor Xa it has been possible to design a synthetic chromogenic peptide substrate. Bz-Ile-Glu-Gly-Arg-pNA, specifically intended for the determination of factor Xa. Furthermore, additional substrates have been synthezised with various alterations in the amino acid sequence. The activity of factor Xa and other serine proteases within the coagulation and fibrinolytic systems towards these substrates will be discussed with special regard to their possible use in coagulation studies.

The Influence of Dipeptide Composition on Protein Folding Rates

2011 ◽  
Vol 378-379 ◽  
pp. 157-160
Author(s):  
Jian Xiu Guo ◽  
Ni Ni Rao
Keyword(s):  
Protein Folding ◽  
Amino Acid ◽  
Amino Acid Sequences ◽  
Dipeptide Composition ◽  
Coupling Effects ◽  
Jackknife Test ◽  
Folding Rates ◽  
Important Challenge ◽  
The Relationship

Understanding the relationship between amino acid sequences and folding rates of proteins is an important challenge in computational and molecular biology. All existing algorithms for predicting protein folding rates have never taken into account the sequence coupling effects. In this work, a novel algorithm was developed for predicting the protein folding rates from amino acid sequences. The prediction was achieved on the basis of dipeptide composition, in which the sequence coupling effects are explicitly included through a series of conditional probability elements. Based on a non-redundant dataset of 99 proteins, the proposed method was found to provide an excellent agreement between the predicted and experimental folding rates of proteins when evaluated with the jackknife test. The correlation coefficient was 87.7% and the standard error was 2.04, which indicated the important contribution from sequence coupling effects to the determination of protein folding rates.

scholarly journals Generation of Affinity Purified Antibody Reagents for Specific Determination of Efruxifermin in Biological Matrices

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A288-A288
Author(s):  
Adam S Kinne ◽  
Sanofar J Abdeen ◽  
Elijah S Parmer ◽  
Jennifer A Thystrup ◽  
Erik J Tillman ◽  
...  
Keyword(s):  
Amino Acid ◽  
Half Life ◽  
Clinical Development ◽  
Amino Acid Sequences ◽  
Fibroblast Growth Factor 21 ◽  
Biological Matrices ◽  
Specific Determination ◽  
Human Igg1 ◽  
Human Fgf21

Abstract Efruxifermin (EFX) is a novel Fc-fusion analog of human fibroblast growth factor 21 (FGF21), currently in clinical development as a potential treatment for non-alcoholic steatohepatitis (NASH). Each molecule of EFX consists of two modified FGF21 molecules, each attached at their N-termini to a human IgG1 Fc domain by a short polyglycine-serine linker. The FGF21 moiety of EFX incorporates three amino acid substitutions (L98R, P171G, and A180E relative to native FGF21). Two of these are proximal to the C-terminus (P171G and A180E), and reduce cleavage and inactivation by an endogenous protease, fibroblast activation protein (FAP), thereby prolonging its half-life. Fusion to human IgG1 Fc domain further extends circulating half-life, enabling once-weekly subcutaneous dosing. Accordingly, to support on-going clinical development of EFX, a specific assay is needed to distinguish intact EFX from both endogenous FGF21 and any in vivo biotransformation products of EFX that display reduced pharmacology. To maximize the antigenicity of EFX, FGF21 amino acid sequences were compared across species. Based on this, an antibody generation campaign was initiated in both rabbits and chickens. Comparison of titer responses against EFX and human FGF21 suggested that antisera from chickens was superior to rabbit antisera. Following a scaled-up, 12-week antibody campaign, antisera were purified by a combination of batch and column chromatographic procedures. By exploiting differences in structure and amino acid sequence of EFX relative to human FGF21, a purification strategy was designed to isolate chicken antibodies with increased specificity for EFX unique sequences. This reagent is being used as a capture antibody in the development of a noncompetitive ECLIA employing chemiluminescence detection. Presently, a number of different antibodies are being evaluated for potential pairing with the specific capture. We conclude that application of affinity purified chicken anti-EFX IgY will enable sensitive and specific determination of EFX in biological matrices with decreased cross-reactivity from endogenous hFGF21 and EFX metabolites.

scholarly journals Succinyl-CoA:(R)-Benzylsuccinate CoA-Transferase: an Enzyme of the Anaerobic Toluene Catabolic Pathway in Denitrifying Bacteria

2001 ◽  
Vol 183 (14) ◽  
pp. 4288-4295 ◽  
Author(s):  
Christina Leutwein ◽  
Johann Heider
Keyword(s):  
Amino Acid ◽  
Electrospray Mass Spectrometry ◽  
Amino Acid Sequences ◽  
Catabolic Pathway ◽  
Methyl Group ◽  
New Family ◽  
Thauera Aromatica ◽  
Coa Transferase ◽  
Similar Amino Acid

ABSTRACT Anaerobic microbial toluene catabolism is initiated by addition of fumarate to the methyl group of toluene, yielding (R)-benzylsuccinate as first intermediate, which is further metabolized via β-oxidation to benzoyl-coenzyme A (CoA) and succinyl-CoA. A specific succinyl-CoA:(R)-benzylsuccinate CoA-transferase activating (R)-benzylsuccinate to the CoA-thioester was purified and characterized from Thauera aromatica. The enzyme is fully reversible and forms exclusively the 2-(R)-benzylsuccinyl-CoA isomer. Only some close chemical analogs of the substrates are accepted by the enzyme: succinate was partially replaced by maleate or methylsuccinate, and (R)-benzylsuccinate was replaced by methylsuccinate, benzylmalonate, or phenylsuccinate. In contrast to all other known CoA-transferases, the enzyme consists of two subunits of similar amino acid sequences and similar sizes (44 and 45 kDa) in an α2β2 conformation. Identity of the subunits with the products of the previously identified toluene-inducedbbsEF genes was confirmed by determination of the exact masses via electrospray-mass spectrometry. The deduced amino acid sequences resemble those of only two other characterized CoA-transferases, oxalyl-CoA:formate CoA-transferase and (E)-cinnamoyl-CoA:(R)-phenyllactate CoA-transferase, which represent a new family of CoA-transferases. As suggested by kinetic analysis, the reaction mechanism of enzymes of this family apparently involves formation of a ternary complex between the enzyme and the two substrates.

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