Plant matrix metalloproteinaseとは 意味・読み方・使い方

Matrix metalloproteinases (MMPs) are zinc endopeptidases, commonly called metzincins. MMP enzymes represent an ancient family of proteins with major similarities in genetic make-up that are present in a range of diverse organisms from unicellular bacteria to multicellular vertebrates and invertebrates. The superfamily is distinguished due to its motif consisting of three histidines bonded to zinc at the catalytic site. The metzincins are divided into four smaller families: seralysins, astacins, adamalysins (ADAMs), and MMPs. The MMP family is formed by twenty related zinc-dependent enzymes. They are noted for having the ability to degrade extracellular matrix proteins, such as collagens, laminin, and proteoglycans. These calcium- and zinc-dependent proteases are activated at neutral pH and twenty-three have been found present in mammalian cells. Plant MMPs show structural similarity to MMPs found in mammals, such as the presence of an auto-regulatory cysteine switch domain and a zinc-binding catalytic domain.
MMPs are synthesized primarily by connective tissues and have a large contribution to the initial events of tissue degradation. There are three major groups of the MMP family and each group has more than one distinct gene product that distinguishes them apart from one another on the immunological and biochemical criteria. Similar to that of induced fit by enzyme-substrate interactions, MMPs in the first group, called collagenases, have interstitial collagens. The second group, called gelatinases, degrade denatured collagens catalytically. The third group, called stromelysins, have the broadest proteolytic action and were originally confused as proteoglyconases. A less clearly described group of MMPs is the PUMP. Its RNA was taken from stromal cells in human breast carcinomas. Based on the PUMP sequence and functionality of carcinomas in the progression of malignancy, a new branch of the MMP family could have been discovered.