5.Study on the impact of Trp1707Ser mutation on the binding mechanism of rF VIII light chain with VWF.
Kun CHI ; Yanyan SHAO ; Yeling LU ; Jing DAI ; Qiulan DING ; Xuefeng WANG ; Hongli WANG
Chinese Journal of Hematology 2014;35(11):995-999
OBJECTIVETo disclose the impact of Trp1707Ser mutation on the binding mechanism of rFVIII light chain (rFVIII LC) with VWF.
METHODSUsing long-chain PCR technique, we constructed rFVIII LC plasmids of both wild type and Trp1707Ser mutant type. BL21 competent cells were used for protein expression. Gradient renaturation was employed to refold protein. SDS-PAGE and Western blot were performed to identify the molecular weight of expressed protein. GST-Sefinose was used for protein purification and surface plasmon resonance (SPR) was employed to detect binding of B-domain-deleted rFVIII (BDD-rFVIII), wild and mutant rFVIII LC with VWF, respectively.
RESULTSThe results of SDS-PAGE and Western blot showed a molecular weight of 110×10(3) of expressed proteins, which were consistent with objective proteins. The expression quantity of wild type was higher than that of mutant type. A concentration-dependent combination of the 3 testing proteins with VWF was found. The KD value of BDDrFVIII (12.2) was lower than that of both rFVIII LCs (wild type 48.9 and mutant type 46.3), whereas there was no discrepancy between wild rFVIII LC and mutant rFVIII LC.
CONCLUSIONTrp1707Ser mutation didn't impact the binding of rFVIII LC expressed by BL21 competent cells with VWF. The heavy chain played a more important role in impacting the binding of FVIII with VWF.
Mutation ; von Willebrand Factor ; genetics
8.Identification of two novel variants of the PCCB gene in a pedigree affected with propionic acidemia.
Qigang ZHANG ; Guanglai FAN ; Shu ZHANG ; Yuefang LIU ; Wenjie ZHANG ; Qiong PAN
Chinese Journal of Medical Genetics 2021;38(3):251-254
OBJECTIVE:
To detect pathogenic variants in a pedigree affected with propionic acidemia (PA).
METHODS:
The proband was subjected to high-throughput next-generation sequencing. Suspected variants were validated by Sanger sequencing of his family members. mRNA was extracted from peripheral blood lymphocytes from the proband's father in order to verify the impact of the splicing variant by RT-PCR combined with Sanger sequencing. The pathogenicity of the missense variant was predicted by using PolyPhen-2, Mutation Taster, SIFT, COBALT and HOPE software.
RESULTS:
The proband was found to harbor compound heterozygous variants of the PCCB gene, namely c.184-2A>G and c.733G>A (p.G245S), which were respectively inherited from his father and mother. RT-PCR combined with Sanger sequencing confirmed skipping of exon 2 during transcription. Bioinformatic analysis indicated the c.733G>A (p.G245S) variant to be damaging.
CONCLUSION
The two variants of the PCCB gene probably underlay the disease in this patient. Above findings have enriched the spectrum of PCCB gene variants.
Exons
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Humans
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Mutation
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Mutation, Missense
;
Pedigree
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Propionic Acidemia/genetics*
9.Factors related to Glycophorin A mutation frequency of workers exposed to benzene..
Li YOU ; Yong-Cheng ZHAO ; Wan-Xin ZHAO ; Qiang LIU ; Ke-Qiu LI ; Da-Wei SHI ; Jin-Long GU ; Ji-Xian WANG
Chinese Journal of Industrial Hygiene and Occupational Diseases 2007;25(11):660-663
OBJECTIVETo analyze related factors which affect GPA mutation frequency of workers exposed to benzene, with the Glycophorin A (GPA) mutation assay and explore the possibility of GPA mutation frequency as an index of predicting the risk of benzene poisoning.
METHODSThe erythrocytes were bound with fluorescent-labeled monoclonal antibody after isolated and fixed from the peripheral blood, and then the GPA mutation assay was performed using the flow cytometry (FCM). The related factors of GPA mutation frequency were analyzed by statistical methods.
RESULTSThe GPA mutation frequency of chronic benzene poisonings was significantly higher than that of their controls (P < 0.05). Significant direct correlation was found between age, length of service, accumulative exposure score and the GPA mutation frequency of workers exposed to benzene (P < 0.01). However, there was significantly inverse correlation between the 3AB index and the GPA mutation frequency (GPAN0: r(s) = -0.589, P < 0.01, GPANN: r(s) = -0.615, P < 0.01). In the multiple factor regression analysis on GPA mutation frequency, benzene exposure and individual susceptibility both entered model of multiple factors analysis, the coefficient of determination of benzene-exposed workers was 0.819.
CONCLUSIONExposure to benzene and individual susceptibility are the most important factors that affect GPA mutation frequency. GPA mutation frequency increases with the benzene exposure and individual susceptibility.
Benzene ; poisoning ; Glycophorin ; genetics ; Humans ; Mutation ; Mutation Rate ; Occupational Exposure
10.Rare thalassemia mutations among southern Chinese population.
Fen LIN ; Liye YANG ; Min LIN ; Xiangbian ZHENG ; Min LU ; Meilan QIU ; Liejun LI ; Longxu XIE
Chinese Journal of Medical Genetics 2017;34(6):792-796
OBJECTIVETo detect rare types of thalassemia mutations among southern Chinese population.
METHODSPeripheral blood samples from 327 patients from various regions of southern China were collected. The patients were suspected as rare-type thalassemia for their inconsistency between hematological phenotypes and results of routine mutation screening. The samples were further analyzed with GAP-PCR and DNA sequencing.
RESULTSOne hundred and eight cases were diagnosed as rare types of thalassemia. Among whom 10 rare α-globin gene mutations including --THAI, HKα, αααanti3.7, αααanti4.2, -α2.8, -α27.6, CD74 GAC>CAC (Hb Q-Thailand), CD30 (-GAG), CD31 AGG>AAG and CD118 (+TCA), and 12 rare β-globin gene mutations including CD37 TGG>TAG, CD39 CAG>TAG/CD39 CAG>TAG, β II-2 (-T), -90(C>T), -31(A>C), -88(C>T), CD7(-A), CD138(+T), CD89-93 (--AGTGAGCTGCACTG), CD54-58 (-TATGGGCAACCCT), Chinese G γ +(A γδβ)0 and Vietnamese HPFH (HPFH-6) were identified. -88(C>T) (HBB: c.-138C>T) and CD39 CAG>TAG (HBB: c.118C>T) were discovered for the first time in Chinese population. CD7(-A) (HBB: c.23delA) and CD138(+T) (HBB: c.416_417insT) were new types of β-globin gene mutations.
CONCLUSIONThe present study have enriched the mutation spectrum of thalassemia in southern China, which has provided necessary information for its diagnosis.
Humans ; Mutation ; Thalassemia ; genetics ; alpha-Globins ; genetics ; beta-Globins ; genetics