Baik Lin Seong

We have generated mutants of Escherichia coli formylmethionine initiator tRNA in which one, two, and all three G X C base pairs in the GGGCCC sequence in the anticodon stem are changed to those found in E. coli elongator methionine tRNA. Overproduction of the mutant tRNAs using M13 recombinants as an expression vector and development of a one-step purification scheme allowed us to purify, characterize, and analyze the function of the mutant tRNAs. After aminoacylation and formylation, the functi

The folding of monomeric antigens and their subsequent assembly into higher ordered structures are crucial for robust and effective production of nanoparticle (NP) vaccines in a timely and reproducible manner. Despite significant advances in <i>in silico</i> design and structure-based assembly, most engineered NPs are refractory to soluble expression and fail to assemble as designed, presenting major challenges in the manufacturing process. The failure is due to a lack of understanding of the ki

We show that the absence of a Watson-Crick base pair at the end of the amino acid acceptor stem, which is a hallmark of all prokaryotic initiator tRNAs, is one of the key features that prevents them from acting as an elongator in protein synthesis. We generated mutants of Escherichia coli formylmethionine tRNA that have a base pair at the end of the acceptor stem. The mutants generated were C1----T1, which had a U.A base pair, A72----G72, which had a C.G base pair, and the C1A72----T1G72 double

Solubility of recombinant proteins (i.e., the extent of soluble versus insoluble expression in heterogeneous hosts) is the first checkpoint criterion for determining recombinant protein quality. However, even soluble proteins often fail to represent functional activity because of the involvement of non-functional, misfolded, soluble aggregates, which compromise recombinant protein quality. Therefore, screening of solubility and folding competence is crucial for improving the quality of recombina

The absence of a Watson-Crick base pair at the end of the amino acid acceptor stem is one of the features which distinguishes prokaryotic initiator tRNAs as a class from all other tRNAs. We show that this structural feature prevents Escherichia coli initiator tRNA from acting as an elongator in protein synthesis in vivo. We generated a mutant of E. coli initiator tRNA in which the anticodon sequence is changed from CAU to CUA (the T35A36 mutant). This mutant tRNA has the potential to read the am

Emerging viruses pose a major threat to humans and livestock with global public health and economic burdens. Vaccination remains an effective tool to reduce this threat, and yet, the conventional cell culture often fails to produce sufficient vaccine dose. As an alternative to cell-culture based vaccine, virus-like particles (VLPs) are considered as a highpriority vaccine strategy against emerging viruses. VLPs represent highly ordered repetitive structures via macromolecular assemblies of viral

There is an unmet public health need for a universal influenza vaccine (UIV) to provide broad and durable protection from influenza virus infections. The identification of broadly protective antibodies and cross-reactive T cells directed to influenza viral targets present a promising prospect for the development of a UIV. Multiple targets for cross-protection have been identified in the stalk and head of hemagglutinin (HA) to develop a UIV. Recently, neuraminidase (NA) has received significant a

While basic mechanisms of several major molecular chaperones are well understood, this machinery has been known to be involved in folding of only limited number of proteins inside the cells. Here, we report a chaperone type of protein folding facilitated by interaction with RNA. When an RNA-binding module is placed at the N-terminus of aggregation-prone target proteins, this module, upon binding with RNA, further promotes the solubility of passenger proteins, potentially leading to enhancement o

Enterokinase and recombinant enterokinase light chain (rEK(L)) have been used widely to cleave fusion proteins with the target sequence of (Asp)(4)-Lys. In this work, we show that their utility as a site-specific cleavage agent is compromised by sporadic cleavage at other sites, albeit at low levels. Further degradation of the fusion protein in cleavage reaction is due to an intrinsic broad specificity of the enzyme rather than to the presence of contaminating proteases. To offer facilitated pur

The non-specific effects (NSEs) of vaccines have been discussed for their potential long-term beneficial effects beyond direct protection against a specific pathogen. Cold-adapted, live attenuated influenza vaccine (CAIV) induces local innate immune responses that provide a broad range of antiviral immunity. Herein, we examined whether X-31ca, a donor virus for CAIVs, provides non-specific cross-protection against respiratory syncytial virus (RSV). The degree of RSV replication was significantly

The durability of antiviral effects of GTE was examined as solution type and powder types over extended periods at various temperature conditions using human influenza A/H1N1 virus. GTE with supplements demonstrated potent viral inactivating activity, resulting in greater than 4 log₁₀ reduction of viral titers even after storage for up to two months at a wide range of temperatures. These data suggest that GTE-based antiviral agents could be formulated as a safe and environmentally fri

The 12 nucleotide conserved sequence at the 3' end of influenza A virion RNA is sufficient to function as a promoter in vitro. By introducing point mutations in all 12 positions of this promoter in model RNA templates and studying the efficiency of RNA synthesis in vitro, we show that only three nucleotides, residues 9, 10 and 11, are crucial for activity, although other nucleotides play a significant but less important role. Additions or deletions within the promoter are tolerated, resulting in