Polymerization of several proteins by Ca2+-independent transglutaminase derived from microorganisms.

Abstract

Casein and soybean globulins were polymerized and gelatinized by Ca2+-independent transglutaminase that was isolated from the culture filtrate of a microorganism thought to belong to Streptoverticillium sp. of actinomycetes. This enzyme polymerized such albumins as bovine serum albumin, human serum albumin and conalbumin in the presence of dithiothreitol. Rabbit myosin was polymerized by the present emzyme but actin was not. An RP-HPLCanalysis after enzymic digestion of the polymerized asl-casein showed existence of the £-(y-Glu)Lys bond. Thus, it was confirmed that the polymerization was formed by a catalytic reaction of the transglutaminase.

Purification and Calcium Dependence of Transglutaminases from Sheep Hair Follicles

“…For the control, 5 mM CaCl 2 was replaced by 5 mM EDTA. After the reaction, the Hammersten casein in the reaction mixture was hydrolyzed by sequential protease digestion by the method of Nonaka et al 22) The digested samples were first fractionated to remove interfering compounds by the method of Sakamoto et al 23 ) The fraction containing e-(y-glutamyl)lysine was collected and derivatized with OPA by the method of Griffin et al 24 ) The OPA-Iabeled e-(y-glutamyl)lysine was injected into reverse phase-HPLC with a Zorbax BP-C8 column (4.6 x 250mm, G-L Sciences) and detected using a fluorescence detector (Ex 334 nm, Em 440 nm). Elution was done with a linear gradient from 20% Solution A and 80% Solution B to 5% Solution A and 95 % Solution B, in which Solution A consisted of 20 mM potassium acetate (pH 5.5) with 1% tetrahydrofuran (THF) and Solution B consisted of methanol with 1 % THF, at a flow rate of 2 ml/min for 20min.…”

Enhancing the Rheological Performance of Wheat Flour Dough with Glucose Oxidase, Transglutaminase or Supplementary Gluten

“…The main action mechanism of the TG enzyme is the catalysis of the acyl-transfer reaction between the ε-amino groups of peptide-bound lysine residues and the γ-carboxyamide group of peptide-bound glutamine residues, resulting in permanent iso-peptide bonds between the gluten chains (Nonaka et al 1989). Besides the ε-amino group of lysine residues, other primary amines can equally serve as substrate for TG; when insufficient primary amines are present, also hydrolysis of glutamine to glutamic acid may take place.…”

Enhancement of microbial transglutaminase production from

“…MTGase from Streptoverticillium sp. used for several food applications such as producing polymers of casein and soybean proteins and gelatinizing sodium caseinate and skim milk gels [12,13].…”