A membrane-bound, cytoplasmic secretory granule found in enzyme-secreting cells and visible by light microscopy. Contain zymogen, an inactive enzyme precursor, often of a digestive enzyme.

Interacting selectively with transfer RNA.

The outer membrane of a zymogen granule.

Enables the directed movement of ammonium into, out of, within or between cells. Ammonium is the cation NH4+ which is formed from N2 by root-nodule bacteria in leguminous plants and is an excretory product in ammonotelic animals.

The regulated release of a substance by a cell or group of cells.

Interacting selectively with a tetrapyrrole, a compound containing four pyrrole nuclei variously substituted and linked to each other through carbons at the alpha position.

The directed movement of substances within a cell.

Catalysis of the transfer of a mannosyl group to an acceptor molecule, typically another carbohydrate or a lipid.

Interacting selectively with any isoprenoid compound, isoprene (2-methylbuta-1,3-diene) or compounds containing or derived from linked isoprene (3-methyl-2-butenylene) residues.

Any process that modulates the frequency, rate or extent of cell killing.

A multi-subunit complex that functions as an antibody and circulates in the blood, lymph, mucosal areas, and other fluids of the body. In its basic form, circulating immunoglobulin is composed of two identical heavy chains and two identical light chains, held together by disulfide bonds. Some forms are polymers of the basic structure and contain additional components such as J-chain and the secretory component.

Interacting selectively with retinol, vitamin A1, 2,6,6-trimethyl-1-(9'-hydroxy-3',7'-dimethylnona-1',3',5',7'-tetraenyl)cyclohex-1-ene, one of the three components that makes up vitamin A. Retinol is an intermediate in the vision cycle and it also plays a role in growth and differentiation.

Any process that stops, prevents or reduces the frequency, rate or extent of cell killing.

The chemical reactions involving retinol, one of the three compounds that makes up vitamin A.