Contact-dependent growth inhibition (CDI) systems enable the direct transfer of protein toxins between competing Gram-negative bacteria. CDI⁺ strains produce cell surface CdiA effector proteins that bind specific receptors on neighboring bacteria to initiate toxin delivery. Three classes of CdiA effectors that recognize different outer membrane protein receptors have been characterized in Escherichia coli to date. Here, we describe a fourth effector class that uses the lipopolysaccharide (LPS) core as a receptor to identify target bacteria. Selection for CDI-resistant target cells yielded waaF and waaP “deep-rough” mutants, which are unable to synthesize the full LPS core. The CDI resistance phenotypes of other waa mutants suggest that phosphorylated inner-core heptose residues form a critical CdiA recognition epitope. Class IV cdi loci also encode putative lysyl acyltransferases (CdiC) that are homologous to enzymes that lipidate repeats-in-toxin (RTX) cytolysins.

We found that catalytically active CdiC is required for full target cell killing activity, and we provide evidence that the acyltransferase appends 3-hydroxydecanoate to a specific Lys residue within the CdiA receptor-binding domain. We propose that the lipid moiety inserts into the hydrophobic leaflet of lipid A to anchor CdiA interactions with the core oligosaccharide. Thus, LPS-binding CDI systems appear to have co-opted an RTX toxin-activating acyltransferase to increase the affinity of CdiA effectors for the target cell outer membrane.

IMPORTANCE Contact-dependent growth inhibition (CDI) is a common form of interbacterial competition in which cells use CdiA effectors to deliver toxic proteins into their neighbors. CdiA recognizes target bacteria through specific receptor molecules on the cell surface. Here, we describe a new family of CdiA proteins that use lipopolysaccharide as a receptor to identify target bacteria.

Target cell recognition is significantly enhanced by a unique fatty acid that is appended to the receptor-binding region of CdiA. We propose that the linked fatty acid inserts into the target cell outer membrane to stabilize the interaction. The CdiA receptor-binding region appears to mimic the biophysical properties of polymyxins, which are potent antibiotics used to disrupt the outer membranes of Gram-negative bacteria.

Although members of the Mycobacterium tuberculosis complex (MTBC) exhibit high similarity, they are characterized by differences with respect to virulence, immune response, and transmissibility. To understand the virulence of these bacteria and identify potential novel therapeutic targets, we systemically investigated the total cell protein contents of virulent H37Rv, attenuated H37Ra, and avirulent M. bovis BCG vaccine strains at the log and stationary phases, based on tandem mass tag (TMT) quantitative proteomics. Data analysis revealed that we obtained deep-coverage protein identification and high quantification.

Although 272 genetic variations were reported in H37Ra and H37Rv, they showed very little expression difference in log and stationary phase. Quantitative comparison revealed H37Ra and H37Rv had significantly dysregulation in log phase (227) compared with stationary phase (61). While BCG and H37Rv, and BCG and H37Ra showed notable differences in stationary phase (1171 and 1124) with respect to log phase (381 and 414). In the log phase, similar patterns of protein abundance were observed between H37Ra and BCG, whereas a more similar expression pattern was observed between H37Rv and H37Ra in the stationary phase.

Bioinformatic analysis revealed that the upregulated proteins detected for H37Rv and H37Ra in log phase were virulence-related factors. In both log and stationary phases, the dysregulated proteins detected for BCG, which have also been identified as M. tuberculosis response proteins under dormancy conditions. We accordingly describe the proteomic profiles of H37Rv, H37Ra, and BCG, which we believe will potentially provide a better understanding of H37Rv pathogenesis, H37Ra attenuation, and BCG immuno protection.

Envelope protein-targeted vaccines for flaviviruses are limited by concerns of antibody-dependent enhancement (ADE) of infections. Nonstructural protein 1 (NS1) provides an alternative vaccine target that avoids this risk since this protein is absent from the virion. Beyond its intracellular role in virus replication, extracellular forms of NS1 function in immune modulation and are recognized by host-derived antibodies. The rational design of NS1-based vaccines requires an extensive understanding of the antigenic sites on NS1, especially those targeted by protective antibodies. Here, we isolated human monoclonal antibodies (MAbs) from individuals previously naturally infected with WNV, mapped their epitopes using structure-guided mutagenesis, and evaluated their efficacy in vivo against lethal WNV challenge.

The most protective epitopes clustered at three antigenic sites that are exposed on cell surface forms of NS1: (i) the wing flexible loop, (ii) the outer, electrostatic surface of the wing, and (iii) the spaghetti loop face of the β-ladder. One additional MAb mapped to the distal tip of the β-ladder and conferred a lower level of protection against WNV despite not binding to NS1 on the surface of infected cells. Our study defines the epitopes and modes of binding of protective anti-NS1 MAb antibodies following WNV infection, which may inform the development of NS1-based countermeasures against flaviviruses.

IMPORTANCE Therapeutic antibodies against flaviviruses often promote neutralization by targeting the envelope protein of the virion. However, this approach is hindered by a possible concern for antibody-dependent enhancement of infection and paradoxical worsening of disease. As an alternative strategy, antibodies targeting flavivirus nonstructural protein 1 (NS1), which is absent from the virion, can protect against disease and do not cause enhanced infection.

Here, we evaluate the structure-function relationships and protective activity of West Nile virus (WNV) NS1-specific monoclonal antibodies (MAbs) isolated from the memory B cells of a naturally infected human donor. We identify several anti-NS1 MAbs that protect mice against lethal WNV challenge and map their epitopes using charge reversal mutagenesis. Antibodies targeting specific regions in the NS1 structure could serve as the basis for countermeasures that control WNV infection in humans.

A number of novel chromone derivatives containing sulfonamide moieties were designed and synthesized, and the activity of compounds against tomato chlorosis virus (ToCV) was assessed using the ToCVCP-oriented screening method. Comparative molecular field analysis (CoMFA) and comparative molecular similarity index analysis (CoMSIA) models were established based on the dissociation constant  values of the target compounds, and compound was designed and synthesized with the aid of CoMFA and CoMSIA models.

The study of affinity interaction indicated that compound  exhibited excellent affinity with ToCVCP with a d value of 0.11 μM, which was better than that of the positive control agents xiangcaoliusuobingmi (0.44 μM) and ningnanmycin (0.79 μM). In addition, the in vivo  inhibitory effect of compound  on the ToCVCP gene was evaluated by the quantitative real-time polymerase chain reaction. ToCVCP gene expression levels of the compound <b>35</b> treatment group were reduced by 67.2%, which was better than that of the positive control agent ningnanmycin (59.5%). Therefore, compound  can be used as a potential anti-ToCV drug in the future.

ELISA kit for Rat Creatine kinase BB isoenzyme (CK-BB)
KTE101077-5platesof96wells	Abbkine	5 plates of 96 wells	EUR 2702.4
Description: Quantitative sandwich ELISA for measuring Rat Creatine kinase BB isoenzyme (CK-BB) in samples from cell culture supernatants, serum, whole blood, plasma and other biological fluids.

ELISA kit for Rat Creatine kinase BB isoenzyme (CK-BB)
KTE101077-96T	Abbkine	96T	EUR 686.4
Description: Quantitative sandwich ELISA for measuring Rat Creatine kinase BB isoenzyme (CK-BB) in samples from cell culture supernatants, serum, whole blood, plasma and other biological fluids.

ELISA kit for Human Creatine kinase BB isoenzyme (CK-BB)
KTE62696-48T	Abbkine	48T	EUR 398.4
Description: Quantitative sandwich ELISA for measuring Human Creatine kinase BB isoenzyme (CK-BB) in samples from cell culture supernatants, serum, whole blood, plasma and other biological fluids.

ELISA kit for Human Creatine kinase BB isoenzyme (CK-BB)
KTE62696-5platesof96wells	Abbkine	5 plates of 96 wells	EUR 2538
Description: Quantitative sandwich ELISA for measuring Human Creatine kinase BB isoenzyme (CK-BB) in samples from cell culture supernatants, serum, whole blood, plasma and other biological fluids.

ELISA kit for Human Creatine kinase BB isoenzyme (CK-BB)
KTE62696-96T	Abbkine	96T	EUR 646.8
Description: Quantitative sandwich ELISA for measuring Human Creatine kinase BB isoenzyme (CK-BB) in samples from cell culture supernatants, serum, whole blood, plasma and other biological fluids.

Recombinant Human Creatine Kinase BB (CK-BB) Isoenzyme
DAG279	Creative Diagnostics	1mg	EUR 1204.8

Human creatine kinase BB isoenzymes?CK-BB ELISA Kit
201-12-1253	SunredBio	96 tests	EUR 528
Description: A quantitative ELISA kit for measuring Human in samples from biological fluids.

Human creatine kinase BB isoenzymes(CK-BB)ELISA Kit
GA-E1269HM-48T	GenAsia Biotech	48T	EUR 346.8

Human creatine kinase BB isoenzymes(CK-BB)ELISA Kit
GA-E1269HM-96T	GenAsia Biotech	96T	EUR 559.2

Human creatine kinase BB isoenzymes(CK-BB)ELISA Kit
QY-E03022	Qayee Biotechnology	96T	EUR 433.2

Human creatine kinase BB isoenzymes，CK-BB ELISA Kit
YLA0168HU-48T	Shanghai YL Biotech	48T	EUR 435

Human creatine kinase BB isoenzymes，CK-BB ELISA Kit
YLA0168HU-96T	Shanghai YL Biotech	96T	EUR 562.5

Recombinant (yeast) Human Creatine Kinase BB Isoenzyme
RP-1058	Alpha Diagnostics	10 ug	EUR 270

Creatine Kinase Isoenzyme MB Assay Kit
abx098421-Hitachi7060R160ml8R260ml2	Abbexa	Hitachi 7060; R1: 60ml×8 R2: 60ml×2	EUR 284.4

Creatine Kinase Isoenzyme MB Assay Kit
abx098421-Hitachi7170R124ml1R26ml1	Abbexa	Hitachi 7170; R1: 24ml×1 R2: 6ml×1	EUR 284.4

Creatine Kinase Isoenzyme MB Assay Kit
abx098421-Hitachi7170R140ml2R220ml1	Abbexa	Hitachi 7170; R1: 40ml×2 R2: 20ml×1	EUR 453.6

Creatine Kinase Isoenzyme MB Assay Kit
abx098421-Hitachi7170R160ml1R215ml1	Abbexa	Hitachi 7170; R1: 60ml×1 R2: 15ml×1	EUR 397.2

Rat Creatine Kinase MB isoenzyme ELISA kit
E02C0085-192T	BlueGene	192 tests	EUR 1524
Description: A competitive ELISA for quantitative measurement of Rat Creatine Kinase MB isoenzyme in samples from blood, plasma, serum, cell culture supernatant and other biological fluids. This is a high quality ELISA kit developped for optimal performance with samples from the particular species.

Rat Creatine Kinase MB isoenzyme ELISA kit
E02C0085-48	BlueGene	1 plate of 48 wells	EUR 624
Description: A competitive ELISA for quantitative measurement of Rat Creatine Kinase MB isoenzyme in samples from blood, plasma, serum, cell culture supernatant and other biological fluids. This is a high quality ELISA kit developped for optimal performance with samples from the particular species.

Rat Creatine Kinase MB isoenzyme ELISA kit
E02C0085-96	BlueGene	1 plate of 96 wells	EUR 822
Description: A competitive ELISA for quantitative measurement of Rat Creatine Kinase MB isoenzyme in samples from blood, plasma, serum, cell culture supernatant and other biological fluids. This is a high quality ELISA kit developped for optimal performance with samples from the particular species.

Dog Creatine Kinase MB isoenzyme ELISA kit
E08C0085-192T	BlueGene	192 tests	EUR 1524
Description: A competitive ELISA for quantitative measurement of Canine Creatine Kinase MB isoenzyme in samples from blood, plasma, serum, cell culture supernatant and other biological fluids. This is a high quality ELISA kit developped for optimal performance with samples from the particular species.

Dog Creatine Kinase MB isoenzyme ELISA kit
E08C0085-48	BlueGene	1 plate of 48 wells	EUR 624
Description: A competitive ELISA for quantitative measurement of Canine Creatine Kinase MB isoenzyme in samples from blood, plasma, serum, cell culture supernatant and other biological fluids. This is a high quality ELISA kit developped for optimal performance with samples from the particular species.

Dog Creatine Kinase MB isoenzyme ELISA kit
E08C0085-96	BlueGene	1 plate of 96 wells	EUR 822
Description: A competitive ELISA for quantitative measurement of Canine Creatine Kinase MB isoenzyme in samples from blood, plasma, serum, cell culture supernatant and other biological fluids. This is a high quality ELISA kit developped for optimal performance with samples from the particular species.

Pig Creatine Kinase MB isoenzyme ELISA kit
E07C0085-192T	BlueGene	192 tests	EUR 1524
Description: A competitive ELISA for quantitative measurement of Porcine Creatine Kinase MB isoenzyme in samples from blood, plasma, serum, cell culture supernatant and other biological fluids. This is a high quality ELISA kit developped for optimal performance with samples from the particular species.

Pig Creatine Kinase MB isoenzyme ELISA kit
E07C0085-48	BlueGene	1 plate of 48 wells	EUR 624
Description: A competitive ELISA for quantitative measurement of Porcine Creatine Kinase MB isoenzyme in samples from blood, plasma, serum, cell culture supernatant and other biological fluids. This is a high quality ELISA kit developped for optimal performance with samples from the particular species.

Pig Creatine Kinase MB isoenzyme ELISA kit
E07C0085-96	BlueGene	1 plate of 96 wells	EUR 822
Description: A competitive ELISA for quantitative measurement of Porcine Creatine Kinase MB isoenzyme in samples from blood, plasma, serum, cell culture supernatant and other biological fluids. This is a high quality ELISA kit developped for optimal performance with samples from the particular species.

Goat Creatine Kinase MB isoenzyme ELISA kit
E06C0085-192T	BlueGene	192 tests	EUR 1524
Description: A competitive ELISA for quantitative measurement of Goat Creatine Kinase MB isoenzyme in samples from blood, plasma, serum, cell culture supernatant and other biological fluids. This is a high quality ELISA kit developped for optimal performance with samples from the particular species.

Goat Creatine Kinase MB isoenzyme ELISA kit
E06C0085-48	BlueGene	1 plate of 48 wells	EUR 624
Description: A competitive ELISA for quantitative measurement of Goat Creatine Kinase MB isoenzyme in samples from blood, plasma, serum, cell culture supernatant and other biological fluids. This is a high quality ELISA kit developped for optimal performance with samples from the particular species.

Goat Creatine Kinase MB isoenzyme ELISA kit
E06C0085-96	BlueGene	1 plate of 96 wells	EUR 822
Description: A competitive ELISA for quantitative measurement of Goat Creatine Kinase MB isoenzyme in samples from blood, plasma, serum, cell culture supernatant and other biological fluids. This is a high quality ELISA kit developped for optimal performance with samples from the particular species.