Abstract
Transglutaminase is a naturally occurring and ubiquitous enzyme which is responsible for the transfer of acyl groups (and resulting crosslinking) between glutamine and lysine residues. Commercial use has been precluded due to the lack of availability and several undesirable characteristics of the mammalian derived enzyme. The recent availability of microbially derived transglutaminase ensures the increased likelihood of human exposure to this substance. In this first of a series of articles evaluating the safety of microbial-deriv ed transglutaminase, the enzyme was tested for acute oral toxicity in the rat and for its mutagenic potential. The acute toxic potential appears to be relatively low given the lack of mortality, morbidity, or signs of toxicity at doses of le; 2,000 mg / kg body weight (bw). Similarly, the enzyme appears to have little if any potential for mutagenesis having been tested in four strains of Salmonella typhimurium (TA98, TA100, TA1535, and TA1537), one tryptophan-dependent Escherichia coli strain (WP2uvrA), with and without activation, the Chinese hamster lung cell line (CHL), with and without activation, and for chromosomal abnormalities in the Slc:ddY male mouse (micronucleus); in all cases found to be without obvious effects. These findings are not surprising given the fact that enzymes are generally considered to be of low toxic potential.