The kinetic characteristics, of interaction between hK6 (human Kallikrein) and soybean (BBI), protease inhibitor and antitumor agent, in the presence of substrate (Phenylalanine –Serine-Arginine)-(7-amino-4- methyl-coumarin) (FSR-AMC) were investigated. The hK6 were found to bind soybean in two reversible steps, by slow binding inhibition mechanism. The Ki of the first step binding was 13 nM and Ki* of the second binding step was 1.6 nM. The microcopic rate constants were calculated as follows: 311 M-1.S-1 for k3 , 0.04×10-6 M-1.S-1 for k –3 , 0.2×10-6 S-1 for k 4 and 0.025×10-6 S-1 for k-4 respectively. The results suggested that the interaction mechanism between hK6 and soybean was like that of trypsin with this inhibitor but with rather lower inhibitory constants values.

Dear Editor, Curcumin is a natural product of Curcuma longa L (turmeric) plant, which has remarkable roles in various biological fields and its properties consist of antioxidant and anti-inflammatory activity, anti-arthritic and anti-diabetic effects, lipid metabolism, protective role against cardiovascular diseases and ischemia, and the regulation of neural process (1). Recently, it has been suggested about the potential effects of Curcumin against pathogenic microorganisms such as bacteria, fungi, and viruses (2). According to the literature, Curcumin has anti-viral effects on virulent viruses such as HIV, HTLV-1, HBV, HCV, HPV, HSV, JEV, influenza, and Coxsackievirus. Although this yellow chemical could be taken into account as a unique antiviral herbal drug, especially for enveloped viruses, it has no toxic effects on the human cell-line viability. Moreover,

Background: Drug resistance is emerging as one of the greatest challenges in the development of effective treatment for HIV infection. The importance of clinical studies in this field stems from the world wide growing of treatment drug-resistant mutations. Objectives: This study was performed to determine the HIV subtype and the resistance mutations to the protease inhibitors in both untreated HIV patients and patients under treatment with protease inhibitors (PIs) in Iran. Methods: The study was conducted on two groups of participants. The first group consisted of 25 HIV patients who did not receive any antiretroviral treatment. The second group included 25 HIV patients who have being treated with a combination of protease inhibitors. After genome extraction, a nested polymerase chain reaction was performed to amplify the protease gene. Upon confirmation using electrophoresis, the amplicons or PCR products were sequenced and analyzed to determine the drug resistance mutations as well as the viral subtypes. Results: Nomutations were found in the first group; however, 32% of the samples in the second group had PI related drug-resistance mutations. The major mutations were V82A and M46I, which were seen in 12% of the samples, while the minor mutation F53L was seen in 16% of the samples. The subtype analysis showed that 94% of the samples were subtype CRF35_AD, and 6% were of defined as subtype A. Conclusions: The present study reports updates on the mutations related to protease resistance in Iranian HIV patients receiving treatment. Our data, as well as existing reports, support the need for the optimization of treatment to prevent emergence of resistant viruses and a search for new antiretroviral drug candidates for HIV patients.