Peptide sequence

About: Peptide sequence is a(n) research topic. Over the lifetime, 84156 publication(s) have been published within this topic receiving 4357443 citation(s).

Calculation of protein extinction coefficients from amino acid sequence data

Abstract: Quantitative study of protein-protein and protein-ligand interactions in solution requires accurate determination of protein concentration. Often, for proteins available only in "molecular biological" amounts, it is difficult or impossible to make an accurate experimental measurement of the molar extinction coefficient of the protein. Yet without a reliable value of this parameter, one cannot determine protein concentrations by the usual uv spectroscopic means. Fortunately, knowledge of amino acid residue sequence and promoter molecular weight (and thus also of amino acid composition) is generally available through the DNA sequence, which is usually accurately known for most such proteins. In this paper we present a method for calculating accurate (to +/- 5% in most cases) molar extinction coefficients for proteins at 280 nm, simply from knowledge of the amino acid composition. The method is calibrated against 18 "normal" globular proteins whose molar extinction coefficients are accurately known, and the assumptions underlying the method, as well as its limitations, are discussed.

Alzheimer's disease: Initial report of the purification and characterization of a novel cerebrovascular amyloid protein

Abstract: A purified protein derived from the twisted beta-pleated sheet fibrils in cerebrovascular amyloidosis associated with Alzheimer's disease has been isolated by Sephadex G-100 column chromatography with 5 M guanidine-HC1 in 1 N acetic acid and by high performance liquid chromatography. Amino acid sequence analysis and a computer search reveals this protein to have no homology with any protein sequenced thus far. This protein may be derived from a unique serum precursor which may provide a diagnostic test for Alzheimer's disease and a means to understand its pathogenesis.

A new method for predicting signal sequence cleavage sites.

Abstract: A new method for identifying secretory signal sequences and for predicting the site of cleavage between a signal sequence and the mature exported protein is described. The predictive accuracy is estimated to be around 75-80% for both prokaryotic and eukaryotic proteins.

Integrins: a family of cell surface receptors.

Abstract: What do cell adhesion, cell migration during embryogenesis, thrombosis, and lymphocyte help and killing have in common? It has recently become clear that these ostensibly unrelated processes all involve related cell surface receptors. This realization comes from sequence data, which show that cell surface receptors for extracellular matrix proteins, a major glycoprotein complex on platelet cell surfaces, and two groups of glycoprotein antigens on lymphoid and myeloid cells all contain homologous subunits. In this brief review, I summarize data from these diverse fields and attempt to clarify the relationships among the members of this family of cell surface receptors.