Papers by Nguyen Hong Loan
Diagnostics
Allopurinol (ALP) is commonly used as a drug for gout treatment. However, ALP is known to cause c... more Allopurinol (ALP) is commonly used as a drug for gout treatment. However, ALP is known to cause cutaneous adverse reactions (CARs) in patients. The HLA-B*58:01 allele is considered a biomarker of severe CAR (SCAR) in patients with gout, with symptoms of Stevens Johnson syndrome, and with toxic epidermal necrolysis. However, in patients with gout and mild cutaneous adverse drug reactions (MCARs), the role of HLA-allele polymorphisms has not been thoroughly investigated. In this study, 50 samples from ALP-tolerant patients and ALP-induced MCARs patients were genotyped in order to examine the polymorphisms of their HLA-A and HLA-B alleles. Our results showed that the frequencies of HLA-A*02:01/HLA-A*24:02 and HLA-A*02:01/HLA-A*29:01, the dual haplotypes in HLA-A, in patients with ALP-induced MCARs were relatively high, at 33.3% (7/21), which was HLA-B*58:01-independent, while the frequency of these dual haplotypes in the HLA-A locus in ALP-tolerant patients was only 3.45% (1/29). The H...
Annals of Translational Medicine, 2015
Human mitochondrial genome consists of 16,569 bp, and replicates independently from the nuclear g... more Human mitochondrial genome consists of 16,569 bp, and replicates independently from the nuclear genome. Mutations in mitochondrial genome are usually causative factors of various metabolic disorders, especially those of encephalomyopathy. DNA analysis is the most reliable method for detection of mitochondrial genome mutations, and accordingly an excellent diagnostic tool for mitochondrial mutation-related diseases. In this study, 19 different mitochondrial genome mutations including A3243G, A3251G, T3271C and T3291C (MELAS); A8344G, T8356C and G8363A (MERRF); G3460A, G11778A and T14484C (LHON); T8993G/C and T9176G (Leigh); A1555G (deafness) and A4225G, G4298A, T10010C, T14727C, T14728C, T14709C (encephalomyopathy in general) were analyzed using PCR-RFLP in combination with DNA sequencing. In addition, a real-time PCR method using locked nucleic acid (LNA) Taqman probe was set up for heteroplasmy determination. Screening of 283 tentatively diagnosed encephalomyopathy patients reveale...
TAP CHI SINH HOC, 2016
Phòng Thí nghiệm trọng điểm Công nghệ Enzym và Protein, Trường Đại học Khoa học tự nhiên 2 Khoa S... more Phòng Thí nghiệm trọng điểm Công nghệ Enzym và Protein, Trường Đại học Khoa học tự nhiên 2 Khoa Sinh học, Trường Đại học Khoa học tự nhiên TÓM TẮT: Dựa trên vị trí cắt đặc hiệu của protease HIV-1, chúng tôi đã thiết kế cơ chất peptide huỳnh quang của protease HIV-1 (ký hiệu peptide HF) theo nguyên tắc FRET (Fluorescence resonance energy transfer). Peptide có trình tự QXL 520-GABA-SFNFPQITK-HiLyte Flour 488-NH 2 , trong đó, cặp huỳnh quang HiLyte Fluor 488/QXL 520 có hệ số phát quang/hấp thụ cao và hoạt động tốt trong điều kiện pH thấp thích hợp cho hoạt tính của protease HIV-1 (pH<5) đã được lựa chọn. QXL 520 chỉ bền khi gắn với gốc serine qua nhóm GABA nên được liên kết với gốc serine có sẵn tại đầu N của peptide HF; trong khi gốc leucine tại đầu C được thay thế bởi lysine liên kết với HiLyte Fluor 488. Các điều kiện phản ứng tối ưu cho xác định hoạt độ protease HIV-1 sử dụng cơ chất peptide HF được xác định là: 100-200 ng protease HIV-1, 2 µM cơ chất peptide HF, đệm CH 3 COONa 100 mM pH 4,7 có NaCl 1 M, EDTA 1 mM, DTT 1 mM, DMSO 5% và BSA 0,5 mg/mL. Peptide HF có thể được bảo quản tốt nhất ở nồng độ 0,1 mg/mL trong DMSO ở-80 o C. Trong các điều kiện phân tích nói trên, protease HIV-1 có ái lực cao với cơ chất peptide HF và thuỷ phân hiệu quả cơ chất này với các hằng số động học V max = 4,45 nM/giây, K cat /K m = 10,89 (mM.giây)-1 gấp khoảng 5 lần khi sử dụng cơ chất thương mại HIV-1 SensoLyte ® 520 HIV-1 Protease Assay (Anaspec, Hoa Kỳ).
Academia Journal of Biology, 2020
Trehalose synthase (TreS, EC 2.4.1.245) is a potential catalyst for synthesis of trehalose, an im... more Trehalose synthase (TreS, EC 2.4.1.245) is a potential catalyst for synthesis of trehalose, an important natural disaccharide. In this study, the treS gene of Pseudomonas putida (VTCC 12263) was cloned into pHT01 plasmid at BamHI-XbaI position, expressed in Bacillus subtilis (B. subtilis) 1012, and characterized. The recombinant TreS had molecular weight of 68 kDa when fused with 8xHis tag at the C-terminus. catalyzed conversion of maltose to trehalose in optimal conditions had specific activity of 1.664 U/g. Expression of TreS was highest when B. subtilis 1012 harboring pHT01-treS was cultured in TB medium at 30 oC, induced with 1.0 mM IPTG when OD600 reached 0.8 and harvested after 10 hours of induction. The recombinant TreS purified by Ni-sepharose chromatography had specific activity of 41.700 U/g and formed a single band on Western blot with monoclonal antibody against His-tag. The recombinant TreS had optimal activity at 37 oC in 100 mM pH 7.4 PBS and 300 mM maltose. It was in...
TAP CHI SINH HOC, 2020
Superroxide dismutase (SOD, EC.1.15.1.1) is the enzyme which dismutates superoxide radicals and p... more Superroxide dismutase (SOD, EC.1.15.1.1) is the enzyme which dismutates superoxide radicals and plays an important role in protection of living cells against oxidative stress. SOD is also involved in immune response in shrimps. In this study, it was found that the total SOD activity of black tiger shrimp muscular tissues is 10 fold higher than that of the haemolymph, however, the specific activity of SOD in the shrimp haemolymph is 9.2 fold higher than that of muscular tissues. By using active gel electrophoresis, 2 different SOD forms were found in black tiger shrimps (one in muscular tissues and two in haemolymph).Using DE-52 cellulose and Q-Sepharose ion exchange column chromatography, one SOD (SOD1) from black tiger shrimp haemolymph was partially purified, and its purity was 31.2 times higher than that of the starting haemolymph. The SOD1 was shown to have mainly one protein band of approximately 24 kDa on SDS-PAGE. SOD1 was most active at 45oC and pH of 5.5. At a concentration...
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Papers by Nguyen Hong Loan