Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.9 (enterokinase)
 675 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effect of severe malnutrition and protein deficiency on small intestine has been documented, but the literature on the effect of mild-to-moderate protein-energy malnutrition (PEM) on small intestine is scant. Mild-to-moderate PEM is most prevalent in India. Twenty-four young rhesus monkeys weighing 1.5-2.0 kg were divided into two groups, control and experimental. Mild-to-moderate PEM was induced in the experimental group by giving half of the required normal diet providing 2.42 g protein.kg-1.day-1 and 55 kcal.kg-1.day-1. Body weight, serum protein, and D-xylose were measured before starting the experiment, at PEM stage, and after rehabilitation. Experimental monkeys representing group I were killed after a 25-30% reduction in body weight along with control group 1 animals at 12 wk. The rest of the experimental animals were rehabilitated for another 10-12 wk and killed along with their respective controls (control group 2). Brush-border membrane vesicles were prepared from three parts of the small intestine. Viable vesicles were used for the uptake of [U-14C]L-proline. Alkaline phosphatase and enterokinase were also measured. Uptake of L-proline amino acid and the activity of both enzymes were found to be decreased significantly in the PEM group; a D-xylose test was abnormal. All animals recovered after rehabilitation. These results indicate that even mild-to-moderate malnutrition affects the absorptive and digestive capacity of the brush border of the small intestine, which reversed back on rehabilitation.
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PMID:Mild-to-moderate malnutrition and small intestine of young rhesus monkeys. 854

The expression of the recombinant diphtheria toxin mutant CRM197 in bacteria other than Corynebacterium diphtheriae has proven to be difficult. Here we propose a new and alternative procedure for the production of full-length CRM197 in Escherichia coli. The present study relates specifically to the expression of an artificial sequence and to a method for the isolation and purification of the corresponding protein. In particular, a synthetic gene coding for CRM197, bearing a short histidine tag and optimized for E. coli codon usage, was cloned in the pET9a vector. Accordingly, the over-expression of the protein was simply induced with arabinose in E. coli BL21AI. The recombinant protein was insoluble and always found inside protein aggregates, which were solubilised using urea. Surprisingly, the expression of CRM197, devoid of the short tag, always failed. Following a refolding step, the his-tagged CRM197 was purified by affinity and gel-filtration chromatography and the purity of the final preparation reached 95%. Interestingly, the recombinant protein features DNase activity, indicating that the presence of the tag is not affecting its biochemical properties. However, the removal of the synthetic tag could be easily obtained by incubating the target protein with a proper quantity of a commercial enterokinase.
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PMID:Overexpression and purification of the recombinant diphtheria toxin variant CRM197 in Escherichia coli. 2188 51