What Is a Protease Inhibitor?

Protease inhibitor broadly refers to a substance that binds to some groups on the active center of a protease molecule to reduce the protease activity or even disappear, but does not denature the enzyme protein. Leuceptin, analgesin, chymostatin, elastase aldehyde, pepsin, and phosphoramidin were isolated from actinomycete fermentation broth, which can inhibit trypsin, papain, chymotrypsin, and elasticity, respectively. Various proteases such as proteases, pepsin, and metalloproteinases. All belong to protease inhibitors.

Peptide-based compounds that either competitively inhibit protease activity or act as inhibitors of complementary protease activity points. These drugs can inhibit the activity of protease, which mainly acts in the final stage of HIV replication. Because the protease is inhibited, the DNA formed from the nucleus of infected CD4 cells cannot be aggregated and released. ^[1]

HIV, etc.

Dr. Joan Stephenson published an article in the Journal of the American Medical Association's "Medical News and Perspectives" and said that researchers in the United States, Canada and Australia found that some patients receiving anti-HIV treatment had abnormal distribution of fat after taking protease inhibitors.

The researchers found that after taking protease inhibitors for 3 months or more, some patients had abnormal deposition of adipose tissue without losing weight, which appeared as "

This product can be used in combination with ritonavir to improve the efficacy of the drug for other anti-therapeutic purposes

The United States Centers for Disease Control and Prevention Hoimberg et al. Reported that the use of protease inhibitors can increase the risk of HIV-1 infection.

According to statistics released by the Ministry of Health in early 2006, as of the end of 2005, about 650,000 people in China were infected with AIDS, and about 60,000 to 80,000 people were newly diagnosed with HIV in 2004, with an average of about 200 new people discovered every day . The rapidly expanding number of patients means a rapidly expanding pharmaceutical market.

Facing the huge market space, the domestic anti-AIDS drug manufacturing enterprises have shown insufficient enthusiasm. The government's bidding system for drugs has kept corporate profits to a minimum. The result of a substantial price reduction in order to compete for orders is the company's independent research and development

Indinavir (indinavir)

Pharmacological effect: a specific protease inhibitor, which is effective against HIV-1.

Pharmaceutical dosage form: 200mg, 400mg capsules.

Pharmacological effect: a specific protease inhibitor, which is effective against HIV-1. Half-life: 1.8 hours.

Drug formulation: oral administration, capsules 400mg, 200mg.

Dosage: The recommended dose is 800 mg orally every 8 hours, and the treatment must start at 2.4 g per day.

Side effects: nausea, diarrhea, fatigue, kidney stones,

Protease is released while the broken cells extract the protein, and these proteases need to be rapidly inhibited to keep the protein from being degraded. During protein extraction, protease inhibitors need to be added to prevent proteolysis. The five common protease inhibitors and their respective action characteristics are listed below. Because the sensitivity of different proteases to different proteins is different, the concentrations of various proteases need to be adjusted. Since the solubility of protease inhibitors in liquids is extremely low, it should be especially noted that when adding human protease inhibitors to the buffer, they should be thoroughly mixed to reduce the precipitation of protease inhibitors.

PMSF

1) Inhibition of serine proteases (such as chymotrypsin, trypsin, thrombin) and thiol proteases (such as papain);

2) 10mg / ml is dissolved in isopropanol;

3) Can be stored at room temperature for one year;

4) Working concentration: 17 ~ 174ug / ml (0.1 ~ 1.0mmol / L);

5) It is unstable in aqueous liquid solutions, and fresh PMSF must be added in each separation and purification step. EDTA

1) Inhibition of metalloproteinases;

2) 0.5mol / L aqueous solution, pH 8 ~ 9;

3) The solution is stable for more than six months at 4 ° C;

4) Working concentration: 0.5 ~ 1.5mmol / L. (0.2 ~ 0.5mg / ml);

5) Add NaOH to adjust the pH of the solution, otherwise EDTA will not dissolve.

Pepsin Inhibitor (pepstantin)

l) Inhibit acid proteases such as pepsin, angiotensinogen, cathepsin D and chymosin;

2) 1mg / ml is dissolved in methanol;

3} The storage solution is stable within 4 weeks at 4 ° C and 6 months at -20 ° C;

4) 1 concentration: 0.7ug / ml (1umol / L)

5) Insoluble in water.

Leupeptin

1) Inhibit serine and thiol proteases, such as papain, plasma enzymes and cathepsin B;

2) 10mg / ml dissolved in water;

3) The storage solution is stable for one week at 4 and 6 months at -20 ;

4) Working concentration is 0.5ug / ml.

Trypsin inhibitor (aprotinin)

1) Inhibition of serine proteases, such as plasma enzymes, relaxin, trypsin and chymotrypsin;

2) 10mg / ml dissolved in water, pH 7 ~ 8

3} Storage solution is stable for one week at 4 and 6 months at -20 ;

4) Working concentration: 0.06 ~ 2.0ug / ml (0.01 ~ 0.3umol / L);

5) Avoid repeated freeze-thaw cycles:

6) Inactivated at pH> 12.8.

Protease inhibitor mixed use

35ug / ml PMSF ... serine protease inhibitor

0.3mg / ml EDTA metalloproteinase inhibitor

0.7ug / ml pepstatin ... acidic protease inhibitor

0.5ug / ml Leupeptin ............ Broad spectrum protease inhibitor