Scale-up production and characterization of anti-human cardiac troponin I monoclonal antibody in ascitic fluid of balb/c mice.

The Human Cardiac Troponin I (hcTnI) is a 210 amino acid protein, 23 kDa in molecular weight. This biomarker is commonly used to diagnose myocardial infarction, micro injury, and acute coronary syndrome (ACS) in patients referring to emergency departments. The American Heart Association (AHA) and European Society of Cardiology (ESC) proposed troponin I as the gold biomarker for early detection of heart attack, especially in myocardial infarction (MI). Therefore, developing monoclonal antibodies against this biomarker could help in for early detection of heart attack. Hybridoma technology is a well-known technique introduced to produce monoclonal antibodies in specialized cells. The aim of this study was to produce large scale of monoclonal antibody against human cardiac troponin I using Hybridoma technology in order to design a diagnostic kit. The monoclonal antibody was produced using conventional Hybridoma technology in ascitic fluid of mouse and characterized for its ability to detect Human Cardiac Troponin I in a rapid test system. The results indicate the successful detection of Troponin I using the obtained monoclonal antibody. According to the achieved results it seems that ascites production of monoclonal antibody is very versatile, inexpensive, and economically useful for monoclonal antibody production.

Modification of a Selective NTRK2 Agonist and Confirmation of Activity in a Glaucoma-on-a-Chip Model.

Purpose: RNYK is a selective agonist of the neurotrophic tyrosine kinase receptor type 2 (NTRK2) which has been screened from a phage-displayed peptide library. Its sequence is SGVYKVAYDWQH, similar to a native NTRK2 ligand, that is, brain-derived neurotrophic factor (BDNF). The current study was performed to recognize and confirm critical residues for RNYK activity in a glaucoma-on-a-chip model. Methods: We designed a modified RNYK (mRNYK) peptide based on hotspots of the RNYK sequence identified by alanine scanning. The critical residues consisted of tyrosine, valine, aspartic acid, and tryptophan (YVDW); however, lysine and glutamine were also maintained in the final sequence (YKVDWQ) for forming amide bonds and peptide dimerization. The affinity of mRNYK binding was confirmed by testing against NTRK2 receptors on the surface of ATRA-treated SH-SY5Y cells. The neuroprotective effect of mRNYK was also evaluated in cell culture after elevated pressure insult in a glaucoma-on-a-chip model. Results: The primary amine on the lysine side-chain from one sequence (YKVDWQ) reacted with a γ-carboxamide group of glutamine from the other sequence, forming dimeric mRNYK. In silico, molecular dynamic simulations of the mRNYK-NTRK2 complex showed more stable and stronger interactions as compared to the RNYK-NTRK2 complex. In vitro, mRNYK demonstrated a neuroprotective effect on SH-SY5Y cells under normal and elevated pressure comparable to RNYK. The 50% effective concentration (logEC50) for mRNYK was 0.7009, which was better than RNYK with a logEC50 of 0.8318. Conclusion: The modified peptide studied herein showed improved stability over the original peptide (RNYK) and demonstrated potential for use as a BDNF agonist with neuroprotective properties for treatment of neurodegenerative disorders such as glaucoma.

Development and characterization of enzyme-linked immunosorbent assay for aflatoxin B1 measurement in urine sample using penicillinase as label.

A simple, sensitive, rapid and specific enzyme linked immunosorbent assay (ELISA) for quantitative measurement of aflatoxin B(1) (AFB(1)) in urine samples was developed in this study. Polyclonal antibodies were raised against a C(1)-carboxymethyl oxime (CMO) derivative of AFB(1) conjugated bovine serum albumin (BSA). AFB(1)-C(8)-penicillinase (AFB(1)-C(8)-P) and AFB(1)-C(1)-carboxymethyl oxime-penicillinase (AFB(1)-CMO-P) were prepared and used as tracer molecule. A heterologous combination of antibody and enzyme conjugates (AFB(1)-C(1)-CMO-BSA and AFB(1)-C(8)-P) proved to work better with respect to specificity and sensitivity. Ig purified antibody (4 microg/well) was coated onto the pre-coated (BSA) wells of microtiter plate. The assay procedure was completed within 3 hr and the sensitivity was calculated to be from 200 pg/ml. The standard curve was linear up to 10 ng/ml so was able to detect high concentration of AFB(1) in sample. Affinities were calculated for homologous and heterologous system in which the heterologous system showed better affinities (1.9 x 10(8) M(-1)). The antibody prepared in this study showed minimal cross-reaction with structurally related molecules being affected by homology and heterology of the assay system that is the site of conjugation of carrier protein for antibody production using the hapten BSA conjugate and the site of enzyme conjugated on the hapten molecule used as tracer as well as direct and indirect coating of antibody on the surface of microtiter plat. The results reported here indicated that the heterologous combination of antibody and enzyme conjugate performs better in assay qualities in general. More than 90% recovery of AFB(1) added to stripped urine samples were observed in this type of assay. Inter and intra-assay percent of coefficient of variations for ten successive assays were found to be 10.2 and 6.9% respectively. Logit -log transformation of standard curve and sample dilution with urine sample containing no AFB(1) in a serial manner exhibited parallel line with the slope of -1.03 and -1.03 respectively. A correlation of 0.90 was found between the ELISA reported in this study and radioimmunoassay (RIA) of AFB(1) in urine samples.