*nase*

n. an enzyme that removes the iodine radical. [ WordNet 1.5 ]

/mhw> n. (Biochem.) any of numerous enzymes that catalyze the breakdown of DNA into oligonucleotides or mononucleotides. [ PJC ]

n. [ Hexose + -kinase. ] (Biochem.) an enzyme catalyzing the transfer of a phosphate residue from ATP to a hexose, as in the formation of glucose-6-phosphate from glucose. [ PJC ]

n. (Biochemistry) One of a class of enzymes that catalyze transfer of a phosphate group from ATP to another molecule; it is a type of phosphorylase. [ PJC ]

(Paint.) A black pigment which dries rapidly when mixed with oil, and is of intense body. Fairholt. [ 1913 Webster ]

n. [ Sp. nispero medlar and naseberry tree, fr. L. mespilus. See Medlar. ] (Bot.) A tropical fruit. See Sapodilla. [ Written also nisberry. ] [ 1913 Webster ]

n. (Bioch.) An enzyme which destroys the antibacterial activity of penicillin by hydrolyzing the amide bond in the beta-lactam ring. Many penicillinases are known, and are produced by a wide variety of bacteria. The production of penicillinase is one of the mechanisms by which bacteria may become resistant to penicillins. Penicillinase production in various bacterial species may be induced, i.e., it may occur only when stimulated by the presence of penicillin in the culture medium, or it may be constitutive, i.e., it may occur whenever the cells are producing protein. Molecular weights of the various penicillinases tend to cluster near 50, 000. [ PJC ]