Aminopeptidase I

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Introductions

Aminopeptidase I is a cytoplasmic to vesicle-targeted (Cvt) cargo protein, an autophagy-like protein-targeting pathway in Saccharomyces cerevisiae, a non-classical vesicular biosynthetic transport pathway. A second enzyme, α-mannosidase, that enters the vesicle along this route also transports by binding directly to the Atg19 receptor and aminopeptidase I. Aminopeptidase I forms a homododecameric complex, which is synthesized and assembled in the cytoplasm, packed in vesicles in double membranes, and transported to the vesicle. The homoduodenal complex of aminopeptidase I has exopeptidase activity towards the amino-terminal leucine residue.

Source

Aminopeptidase, a protease, is widely found in organisms of different species, including mammals, plants, microorganisms, etc. Due to the complex composition and low content of aminopeptidase in plants and animals, it leads to high extraction cost. With the rapid development of enzyme preparation industry, in order to meet the market demand, the production of enzyme by microbial fermentation has become the mainstream trend and research hotspot today reported a wide range of aminopeptidase-producing microorganisms, mainly divided into two major categories: one is eukaryotic microorganisms, including Trichoderma, Penicillium, Aspergillus, Yeast family, etc.; the other is prokaryotic microorganisms, including Pseudomonas, Lactobacillus, Bacillus, Actinomyces, etc.

Applications

• Deep hydrolysis of proteins

In combination with proteases, the degree of protein hydrolysis can be substantially increased. In the preparation of soy sauce brewing, cheese production and other protein hydrolysis products, it can improve the protein utilization and save cost. For example, Cui Chun and Zhao Mouming used flavor protease (a complex of protease and aminopeptidase) to deeply enzymatically digest blue garden fish ginseng protein, and the protein utilization rate reached 83.3% after 6h of enzymatic digestion, and the hydrolysis degree reached 59.7% at 21h.

• Preparation of bioactive peptides

Most of the bioactive peptides are cell growth factors, which have very low content in the body but high biological activity, and play a biological regulatory role on many cell physiological functions and metabolic activities. They have health and beauty functions. The controlled enzymatic digestion of proteins to obtain specific active peptides is a safe and efficient way to prepare active peptides. Liu et al. first hydrolyzed soybean isolate with protease and then with aminopeptidase, and found that the peptide content in the product could be increased by about 12% compared to single hydrolysis with protease.

• Special use in medicine

Aminopeptidase can effectively scavenge neurotoxic chemical agents and organophosphorus pesticides, and can be used as both a medical antidote and an environmental disinfectant. Leucyl aminopeptidase and other enzymes can also be used as molecular tools for protein sequence determination.

Production

Aminopeptidases are widely distributed in nature, and there are large differences in expression and substrate specificity among different sources of aminopeptidases. The extraction of aminopeptidases from plants and animals is more complicated and costly, therefore, the extraction of related aminopeptidases from plants and animals is generally used for the characterization of enzymatic properties and the diagnosis of related diseases. Compared with plant and animal enzymes, microorganisms produce higher amounts of enzymes, simpler extraction steps and lower production costs, and the aminopeptidase products on the market are basically produced by microbial fermentation.