Specificity of guinea pig liver transglutaminase for amine substrates

Abstract

The amine specificity of guinea pig liver transglutaminase, a model enzyme for endo-gamma-glutamine:epsilon-lysin transferases, was explored with the aid of synthetic substrates of high apparent affinities. As exemplified by dansyl- (5-dimethylamino-1-naphthalenesulfonyl), (2,4-dinitrobenzenesulfonyl)-, and (2,4,6-triisopropylbenzenesulfonyl)-cadaverines--each of which showed affinities of approximately 4 x 10(7) M-1--the best amine substrates carried a large hydrophobic substituent attached to an alkylamine side chain of about 7.2 A in length. Altogether, our results point to the importance of a hydrophobic binding region in the enzyme from where the alkyl side chain reaches into a narrow crevice toward the active center and positions the primary amine of the substrate for attacking the carbonyl group of the acyl enzyme intermediate.

Tissue transglutaminase-induced aggregation of α-synuclein: Implications for Lewy body formation in Parkinson's disease and dementia with Lewy bodies

“…CTM is known to inhibit tTGase activity through a disulfide exchange reaction and serves as a competitor for tTGase by blocking access of the glutamine residue in substrate proteins to the active site of the enzyme (41,42). Therefore, we examined whether CTM is able to inhibit tTGase-induced ␣-synuclein aggregation in a cellular model.…”

Contribution of fibrin stabilization to clot strength. Supplementation of factor XIII-deficient plasma with the purified zymogen.

“…It is known that primary amines, depending on their structure and pKa, show different potencies for inhibiting fibrin stabilization when examined by the criterion of clot solubility in 1% monochloroacetic acid (7). Of the compounds available, we have chosen representative small amines (hydroxylamine and aminoacetonitrile), some large monosubstituted cadaverines with various apolar (2,4-dinitrophenyl, mesitylenesulfonyl, and dansyl) residues and dansylthiacadaverine (18).…”

“…of the primary ammonium ions. If, instead of the total added concentration of a given amine (i.e., the sum of amine and ammonium ion forms), the effective concentration of the deprotonated nucleophile that is considered to be the inhibitory species (7,18) was calculated for the pH of the experiment (pH 7.6), a completely different appraisal emerged. The data, together with the chemical structures and pKa of the inhibitors, are given in Table I 100 50 Y --00 and, for the series examined, the relative order of inhibitory potencies (in square brackets) was dansylcadaverine -mesitylenesulfonylcadaverine, [9,000], dansylthiacadaverine, [4,514], 2,4-dinitrophenylcadaverine, [1,514], aminoacetonitrile, [2], and hydroxylamine [1].…”

Gelation of Bean 11S Globulins by Ca2+-Independent Transglutaminase

“…Quantitative analyses of the s-(y-glutamyl)lysyl isopeptide bonds measured by the method of Oriffin et al 28 ) showed that similar amounts of isopeptide bonds were formed in glycinin and legumin after incubation with TO for various times (data not shown). Chemical analyses for lysine and glutamine residues by the method of Field 29 ) and Lorand et al, 30) respectively, indicate that both 11 S globulins have similar number of surface glutamine and lysine residues. The number of surface lysines in glycinin and legumin was 13 and 11 per molecule, respectively.…”