Activity

Eukaryotic recombinant proteins expressed in bacterial cells usually aggregate within the cells as inclusion bodies. Despite the widely-accepted theory considering inclusion bodies as inactive materials, inclusion bodies may contain large amounts of correctly-folded active recombinant proteins. Proteins trapped in inclusion bodies can be released using a high pH solution (pH ≥ 11); however, they may undergo structural changes in such pH conditions that may lead to their inactivation. Shifting in pH alongside the use of metal ions can help recover protein activity. The model protein we used in this study, 9R-Nimo.scFv, is highly active when extracted from bacterial inclusion bodies at high pH condition (pH 12) but loses its activity when pH is reduced to pH 7. We evaluated the capacity of nine salt solutions in terms of recovering protein activity in neutral pH conditions and found that ZnSO4 solution was the best one for this purpose. KNO3 and MnSO4 were also found to have a good capacity for recovering protein activity, as well. Chinese mitten crab Eriocheir sinensis is probably the most important freshwater cultured crab in China. A tiny minority of brownish-orange individuals have been discovered in the long period of artificial breeding history of E. sinensiss. Those mutants are usually accompanied with slow growth rate, low molting frequency and poor survival rate, which may be the results of growth defects and immunodeficiency. To better understand the relationship between body color determination and the immune system as well as the related genes expression in E. sinensiss, we performed the whole-body transcriptome analysis in different color of first stage zoea (ZI) larvae using next-generation sequencing (NGS) technology. We randomly assembled 175.40 and 177.52million clean reads from the wild and mutant ZIs, respectively. Finally, we identified 7153 differentially expressed genes (DEGs) (p  less then  0.05), with 5194 up-regulated and 1959 down-regulated. A total of 13 KEGG pathways related to immune system were detected among 248 pathways. Except the first whole-body RNA sequencing of color-specific transcriptomes for E. sinensis, this study will offer a better understanding of the underlying molecular mechanisms of interaction between color determination and the immune system. Interleukin 11 (IL-11) is a secretory cytokine with pleotropic properties, including anti-inflammatory and anti-apoptotic functions. This study aimed to functionally characterize a teleostean IL-11a ortholog from redlip mullet (LhIL-11a) through bioinformatic analysis, transcriptional expression profiling and protein function assays. The deduced LhIL-11a protein sequence is 200 amino acids long, with a predicted molecular weight of 23.168 kDa. Multiple sequence alignment indicates that LhIL-11a has a typical four-bundle architecture of α-helixes as observed in other IL-11s. The identity-similarity matrix show a higher identity between LhIL-11a and other fish IL-11a sequences. Phylogenetic analysis demonstrated that LhIL-11a falls within a clade including other fish counterparts. In the tissue distribution analysis, the highest constitutive expression of LhIL-11a mRNA was observed in the mullet gastrointestinal tract and brain tissues. Following the challenges with LPS, poly IC and Lactococcus garvie, the transcription levels of LhIL-11a were significantly upregulated in both PBCs and liver. In the biological functional assay, recombinant LhIL-11a protein showed strong activities of suppressing pro-inflammatory cytokines and apoptotic gene expression in mullet kidney cells and reducing LPS stimulated NO production in murine macrophage cells. Overall, the findings in this study provide the experimental clues to understanding the functional roles of fish IL-11a in inflammation and apoptosis regulation during host defense against invading microbial pathogens. Cathepsin K belongs to the family of cysteine cathepsins. It is well known that the cysteine cathepsins participate in various physiological processes and host immune defense in mammals. However, in teleost fish, the function of cathepsin K is very limited. In the present study, a cathepsin K homologue (SsCTSK) from the teleost black rockfish (Sebastes schlegelii) was identified and examined at expression and functional levels. In silico analysis showed that three domains, including signal peptide, cathepsin propeptide inhibitor I29 domain, and functional domain Pept_C1, are existed in SsCTSK. SsCTSK also possesses a peptidase domain with three catalytically essential residues (Cys25, His162 and Asn183). Phylogenetic profiling indicated that SsCTSK was evolutionally close to the cathepsin K of other teleost fish. Expression of SsCTSK occurred in multiple tissues and was induced by bacterial infection. Purified recombinant SsCTSK (rSsCTSK) exhibited apparent maximal peptidase activity at 45 °C, and its enzymatic activity was remarkably declined in the presence of the cathepsin inhibitor E-64. Moreover, rSsCTSK possesses the ability to bind with PAMPs and bacteria. Finally, knockdown of SsCTSK expression facilitated bacterial invasion in black rockfish. Collectively, these results indicated that SsCTSK functions as a cysteine protease and may serves as a target for pathogen manipulation of host defense system. A relatively large repertoire of type I interferon (IFN) genes is apparent in rainbow trout/Atlantic salmon, that includes six different IFN subgroups (IFNa-IFNf) belonging to the three known type I IFN groups (1-3) in bony fish. Whether this is true for other salmonids, and how the various type I subgroups evolved in teleost fish was studied using the extensive genomic resources available for fish. This confirmed that salmonids, at least the Salmoninae, indeed have a complex (in terms of IFN subgroups present) and large (number of genes) IFN repertoire relative to other teleost fish. This is in part a consequence of the salmonid 4 R WGD that duplicated the growth hormone (GH) locus in which type I IFNs are generally located. EUK 134 clinical trial Divergence of the IFN genes at the two GH loci was apparent but was not seen in common carp, a species that also underwent an independent 4 R WGD. However, expansion of IFN gene number can be found at the CD79b locus of some perciform fish (both freshwater and marine), with expansion of the IFNd gene repertoire.