negative regulation of natural killer cell activity

Any process that stops, prevents or reduces the rate, frequency or extent of natural killer cell activity.

The regulated release of vasopressin from secretory granules into the blood.

Any of the processes involved in the maintenance of an internal equilibrium of water within an organism or cell.

Catalysis of the reaction: cyclobutadipyrimidine (in DNA) = 2 pyrimidine residues (in DNA). The enzyme catalyzes the reactivation by light of irradiated DNA. A similar reactivation of irradiated RNA is probably due to a separate enzyme.

Catalysis of the hydrolysis of alkylated DNA; recognizes and removes alkylated purines and pyrimidines by cleaving the N-C1' glycosidic bond between the target damaged DNA base and the deoxyribose sugar. The reaction releases a free base and leaves an apurinic or apyrimidinic (AP) site. Enzyme has broad substrate specificity, being able to recognize alkylpurines, alkylpyrimidines or ethenopurines.

major histocompatibility complex class I receptor

A major histocompatibility complex class I receptor. These display processed antigens from the endocytosed bacteria. MHC class I proteins can form complexes with processed antigen peptides only if the antigen is synthesized in the same cell. As a consequence, T lymphocytes can only bind to class-I-positive cells that are synthesizing the antigen (e.g. virus-infected cells).

DNA-(apurinic or apyrimidinic site) lyase activity

Catalysis of the cleavage of the C-O-P bond 3' to the apurinic or apyrimidinic site in DNA by a beta-elimination reaction, leaving a 3'-terminal unsaturated sugar and a product with a terminal 5'-phosphate.

Catalysis of the reaction: DNA (containing 6-O-methylguanine) + (protein)-L-cysteine = DNA (without 6-O-methylguanine) + protein S-methyl-L-cysteine.

metal incorporation into metallo-sulfur cluster

metal incorporation into metallo-sulphur cluster

The formation of a cluster of several metal atoms, including iron, nickel, molybdenum, vanadium, or copper, with one or more bridging (mu-bond) sulfur atoms; amino acids residues in proteins that may ligate the metal sulfur cluster are cysteine, histidine, aspartate, glutamate, serine and cysteine persulfide.