Amino acid sequences requirements for

The common C-terminal amino acid sequence required for exerting activity at tachykinin receptors is shown in bold endokinin C and D lack the C-terminal Met and are almost devoid of affinity at these receptors. In red, the sequence of neurokinin A of which neuropeptide-gamma and neuropeptide-kappa are elongated forms and neurokinin A (3-10) is a product of beta or gamma-TAC1 mRNAs or an NKA metabolite active at tachykinin receptors. In blue, the sequence of human HK-1 of which endokinin A and B are elongated forms. 

Hamada, K., Terashima, H., Arisawa, M., and Kitada, K. (1998b). Amino acid sequence requirement for efficient incorporation of glycosylphosphtidylinositol-associated proteins into the cell wall of Saccharomyces cerevisiae. J. Biol. Chem. 273, 26946—26953. 

The separation of the target protein from the fusion protein can be performed chemically or enzymatically. The basis for chemical cleavage is acid or base stability of the target protein. Enzymatic separation by proteases is highly specific but its efficiency can be decreased by limited access to the part of the amino acid sequence required for proteolysis. 

The CASE methodology has been modified to be usable for the evaluation of the amino acid sequences required for activity. The procedure calls for fragmentation of the peptide chain in fragments of 3 to 10 constituent units. These formerly consisted of heavy... 

Popelkova H, Im M, Yocum CF. N-terminal truncations of manganese stabilizing protein identify two amino acid sequences required for binding of the eukaryotic protein to photosystem II, and reveal the absence of one binding-related sequence in cyanobacteria. Biochemistry 2002 ... 

K. E. Coyne, A. Crisci D. M. Lublin. Construction of synthetic signals for glycosyl-phosphatidylinositol anchor attachment. Analysis of amino acid sequence requirements for anchoring. J Biol Chem, 1993, 268, 6689-6693. 

In the synthesis of polypeptides with biological activity on a crosslinked polymer support as pioneered by Merrifield (1 2) a strict control of the amino acid sequence requires that each of the consecutive reactions should go virtually to completion. Thus, for the preparation of a polypeptide with 60 amino acid residues, even an average conversion of 99% would contaminate the product with an unacceptable amount of "defect chains". Yet, it has been observed (13) that with a large excess of an amino acid reagent —Tn the solution reacting with a polymer-bound polypeptide, the reaction kinetics deviate significantly from the expected exponential approach to quantitative conversion, indicating that the reactive sites on the polymer are not equally reactive. 

Westaway (1977) has proposed that three structural polypeptides, C, E, and M as well as five nonstructural polypeptides are separately initiated and terminated during translation, which would make the flavivirus mRNA unique since most other animal mRNAs studied to date have only a single translation initiation site, with a few exceptions (Kozak, 1981 Strauss and Strauss, 1983). On the other hand, Wengler et al. (1979) and Svitkin et al. (1981) reported that in an in vitro translation system only a single initiation site appeared to be used. The entire sequence of the flavivirus genome as well as amino acid sequence data for the polypeptides will be required to decide between these alternative translation strategies. 

The World Wide Web has transformed the way in which we obtain and analyze published information on proteins. What only a few years ago would take days or weeks and require the use of expensive computer workstations can now be achieved in a few minutes or hours using personal computers, both PCs and Macintosh, connected to the internet. The Web contains hundreds of sites of Interest to molecular biologists, many of which are listed in Pedro s BioMolecular Research Tools (http // www.fmi.ch/biology/research tools.html). Many sites provide free access to databases that make it very easy to obtain information on structurally related proteins, the amino acid sequences of homologous proteins, relevant literature references, medical information and metabolic pathways. This development has opened up new opportunities for even non-specialists to view and manipulate a structure of interest or to carry out amino-acid sequence comparisons, and one can now rapidly obtain an overview of a particular area of molecular biology. We shall here describe some Web sites that are of interest from a structural point of view. Updated links to these sites can be found in the Introduction to Protein Structure Web site (http // WWW.ProteinStructure.com/). 

The classical cadherins are translated as precursor because they are N-terminally cleaved to reveal the mature proteins. This processing is required to activate the cell adhesion function of cadherins. Cadherins interact in trans (i.e., from opposite cells) via the most N-terminal cadherin rqDeats. A short amino acid sequence within this repeat, histidine-alanine-valine (HAV), has been implicated in mediating cell-cell contacts as HAV peptides can disrupt cadherin-dependent cell adhesion. Besides the trans-interactions of cadherins, the extracellular domains are also capable of forming cis-dimers through lateral amino acid contacts between cadherin molecules on one cell. This dimerization again mainly involves the first cadherin repeat. A zipper model based on the pattern of alternating cis- and trans-dimers [1] for the adhesive interactions has been proposed. 

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