Elafin was shown to be a new type of proteinase inhibitor which has an anchoring sequence. Human elafin, a potent inhibitor specific for elastase and proteinase 3, has a unique repeating sequence in its prosegment that is rich in Gln and Lys residues. The prosegment, termed "cementoin," exhibits high homology with the repetitive element of seminal vesicle clotting protein, which is known as a good substrate for prostate transglutaminase. The cross-linking of cementoin by tissue transglutaminase showed that the cementoin moiety is indeed a preferable substrate for transglutaminase. In addition, transglutaminase-mediated cross-linking between cementoin and laminin was observed in vitro, suggesting that cementoin has the ability to covalently attach to other extracellular matrix proteins. To determine whether or not this type of covalent gluing of elafin through the cementoin moiety occurs in vivo, we determined the molecular size of cementoin-elafin in the trachea mucous epithelium by Western blotting; the rationale of this approach is that (i) the trachea is the richest source of cementoin-elafin, as shown below, and (ii) if cementoin-elafin is covalently associated with other proteins, it should migrate as a higher M(r) species on SDS-polyacrylamide gel electrophoresis; cementoin-elafin immunoreactivity was indeed detected at a position corresponding to 50 kDa, a value much higher than that of its monomeric form. RNase protection analysis and immunohistochemical staining revealed that cementoin-elafin is densely distributed in the skin and trachea, and moderately in the stomach, duodenum and small intestine. These sites of localization are consistent with the locations where elastic fibers are abundant.(ABSTRACT TRUNCATED AT 250 WORDS)

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BackgroundThis study aimed to evaluate the levels of thyroid hormones and lactate dehydrogenase (LDH) isoenzymes in obese and/or diabetic patients.Subjects and methodsForty male subjects categorized into four equal groups; group 1: Non obese control subjects, group 2: Subjects suffering from type 2 diabetes mellitus (T2DM), group 3: Obese subjects (BMI ≥ 30 kg/m2) and group 4: Subjects thatwere obese and had type 2 diabetes mellitus (T2DM). Liver, kidney, lipid, thyroid hormones, total LDH and LDH isoenzymes levels were determined.ResultsThere was a significant increase of TSH level (p<0.001) in diabetic group as compared with control group and a highly significant increase of TSH was obtained in obese and obese diabetic groups versus control and diabetic patients. LDH 2 was also highly significantly decreased in obese and obese diabetic groups versus diabetic patients. Percentage of LDH 4 was significantly decreased in both diabetic and obese groups and not significantly changed in obese diabetic patients as compared with the control group. LDH 5 percentage showed very highly significant decrease in diabetic, obese and highly significant decrease in obese diabetic groups when compared with control subjects while it was not significantly changed in obese and obese diabetic groups as compared with diabetic patients.ConclusionLDH isozymes can be used as valuable diagnostic markers for metabolic syndrome. This may help to explore the metabolic changes associated with obesity and diabetes complication and following up the complication of these abnormalities.

SUMMARY Histidine-tagged green fluorescent protein (His6-Xpress-GFP), a widely used fluorescent probe, was found to be a good substrate for transglutaminase, an enzyme that catalyzes covalent crosslinking of proteins. GFP alone did not serve as a substrate but its derivative His6-Xpress-GFP was readily crosslinked through the Gln and Lys residues present in the short N-terminal extension (His6-Xpress). His6-Xpress-GFP was sensitive enough to detect the transglutaminase activity in guinea pig liver homogenates. The fluorescent substrate could also be used for activity staining of transglutaminase on histological tissue sections, and such applications revealed a surprisingly wide distribution of transglutaminase in the body, especially in the extracellular matrices of various tissues, suggesting an important role for transglutaminase in maintaining the integrity of the extracellular matrix and connective tissues by crosslinking its constituent proteins.(J Histochem Cytochem 49:247–258, 2001)