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Background: StrongestPath is a Cytoscape 3 application that enables the analysis of interactions between two proteins or groups of proteins in a collection of protein-protein interaction (PPI) network or signaling network databases. When there are different levels of confidence over the interactions, the application is able to process them and identify the cascade of interactions with the highest total confidence score. Given a set of proteins, StrongestPath can extract a set of possible interactions between the input proteins, and expand the network by adding new proteins that have the most interactions with highest total confidence to the current network of proteins. The application can also identify any activating or inhibitory regulatory paths between two distinct sets of transcription factors and target genes. This application can be used on the built-in human and mouse PPI or signaling databases, or any user-provided database for some organism., Results: Our results on 12 signaling pathways from the NetPath database demonstrate that the application can be used for indicating proteins which may play significant roles in a pathway by finding the strongest path(s) in the PPI or signaling network., Conclusion: Easy access to multiple public large databases, generating output in a short time, addressing some key challenges in one platform, and providing a user-friendly graphical interface make StrongestPath an extremely useful application.

Background and the purpose of the study: Heat Shock Protein 90 (Hsp90) is typically the most abundant chaperone in the eukaryotic cell cytoplasm, and its expression is essential for loading immunogenic peptides onto major histocompatibility complex molecules for presentation to T-cells. Therefore, it may act as a good candidate as an adjuvant molecule in vaccine technology. Methods: Initially the human Hsp90β gene was cloned into the heat inducible expression vector pGP1-2 and then the recombinant protein was isolated by ion exchange chromatography. After intradermal injection of confirmed purified band of protein to rabbits and isolation of the serum IgG antibody, for its affinity purification, the rabbit's purified Hsp90 specific IgG was coupled to the cyanogen bromide-activated Sepharose 4B. Results: The recovery of the purified protein of interest by affinity chromatography was 50%. Conclusion: This research enabled purification of human heat shock protein by a laboratory prepared column chromatography. [ABSTRACT FROM AUTHOR]

A splice form of prochymosin lacking exon-6 was subcloned and expressed. Expression was optimized by changing various parameters. The maximum amount of protein expressed by this method was 44.61% of total cellular protein, compared to the 45.4% predicted by the Qualitek-4 software. The expressed protein was then purified using ion exchange chromatography. Activation of the recombinant prochymosin was carried out by changing different parameters. Optimal conditions for activation involved reduction of pH to 5 and 4 h of incubation with the acidic solution, followed by neutralization and 2 h of incubation under neutralized conditions. The activity of the subsequent enzyme sample was 26 units/mL. [ABSTRACT FROM AUTHOR]

Enzymatic hydrolysis has been widely applied for production of protein hydrolysate from shrimp waste and for purification of chitin. In the present study, shrimp (P. semisulcatus) head waste was hydrolysed, using a commercial proteolytic enzyme, Alcalase. In order to improve protein extraction efficiency, certain chemicals such as sodium sulphite and Triton x-100 were used along with the enzyme. When Alcalase (12 AU/kg) used alone, the yield of protein extraction was 45.1% and by using Triton x-100 (0.01 g/kg) together with Alcalase, the yield was decreased to 39%, whereas the presence of sodium sulphite (200 mmol/L) with the enzyme or with the enzyme and Triton x-100 increased the level of protein extraction to 62% and 65.1%, respectively. The resulting protein powder contained sufficient amounts of essential amino acids to be used in feed formulations. By precipitating proteins from the resulting protein extract at pH = 3.1, the residual sulphite in protein powder was decreased by 97% and thus the powder can be considered suitable for animal and/or aquaculture feed formulations. [ABSTRACT FROM AUTHOR]