Transit peptide prediction

Emanuelsson, O., Nielsen, H., and von Heijne, G. (1999). ChloroP, a neural network-based method for predicting chloroplast transit peptides and their cleavage sites. Protein Sd. 8, 978—984. 

The truncated PHYLLO menFS module product showed homology to the N-terminal part of ICS, and hence it was important to establish whether it is functional. Hence, plants containing single and double knockouts of the genes ICSl and ICS2) were tested. It was found that only the double knockout plants showed the expected pha phenotype, demonstrating that ICSl and ICSl overlap in their function for the synthesis of isochorismate required for K. This experiment in addition established that the product of the menFS module is unable to complement K deficiency. The PHYLLO product was found to contain 1715 deduced amino acid residues with the four Men modules and a predicted transit peptide that directs the protein to the chloroplasts. 

Target (htq) //www.cbs.dtu.dk/servicesA argetP/) assigns the subcellular location of proteins based on the predictions of the N-terminal chloroplast transit peptide, mitochondrial targeting peptide or secretory signal peptide. 

Prior investigations on enantioselective aldol additions by Wennemers and coworkers in 2007 demonstrated the crucial relevance of the secondary amine at the N-terminus, the carboxylic acid in the side chain and a well-defined p-turn conformation of H-Pro-Pro-Asp-NH2-type proteins for the high catalytic activity and selectivity Thus, the employment of tripeptides comprising this motive was expanded to the 1,4-addition of aldehydes to nitro-olefins and nitroethylene (Scheme 13.12a) ° Peptide 15a comprising D-proline at the N-terminus showed the best catalytical performance for the addition of a series of aliphatic and aromatic aldehydes to aliphatic and aromatic nitro-olefins with good to excellent yields and excellent enantioselec-tivity The proposed transition states for both 15a and the above-mentioned parent peptide predicts the formation of the enantiomeric products. 

The BI02 gene of A. thaliana is interrupted by five introns. The gene codes for a protein of 379 amino acids, with a predicted molecular mass of 41 kDa. The A. thaliana biotin synthase has an N-terminal extension (compared to the bacterial enzyme), which has features indicating it may act as a mitochondrial transit peptide. This would indicate that biotin biosynthesis occurs within mitochondria of plant cells. Indeed, biotin biosynthesis may be derived from pimelic acid, which may be a product of a mitochondrial fatty acid synthase. In situ analyses of the accumulation of the biotin synthase mRNA indicates that the spatial pattern of accumulation changes during the development of the siliques. Namely, whereas the mRNA is present throughout the... 

With continuous development of systems for controlled drug release, new materials are being used whose influence on peptide stability must be carefully examined. Thus, the model hexapeptide Val-Tyr-Pro-Asn-Gly-Ala (Fig. 6.30) embedded in poly (vinyl alcohol) and poly(vinyl pyrrolidone) matrices had rates of deamidation that increased with increasing water content or water activity, and, hence, with decreasing glass transition temperature (Tg). However, the degradation behavior in the two polymers differed so that chemical reactivity could not be predicted from water content, water activity, or T% alone. Furthermore, the hexapeptide was less stable in such hydrated polymeric matrices than in aqueous buffer or lyophilized polymer-free powders [132],... 

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