Expression and Characterization of Human Heart Type Fatty Acid Binding Protein in Pichia Pastoris

H-FABP is regarded as a tissue-specific protein existing only in myocardial cells. It is released from the cardiac tissue and gets into the plasma when a heart attack occurs; the myocardial infarction is a good case in point. As a resuit, the detection of H-FABP will be an early and important biomarker for the disease concerned. The objective of the study is to prepare the recombinant H-FABP by aeukaryotic expression system, pichia, to produce the protein mimicking natural H-FABP, as an immunogen for the production of the specific antibody. A gene fragment encoding H-FABP was cloned in the expressing vector pPICZα, after sequencing. The recombinant plasmid was transformed into the competent cells of the X-33 strain by means of electroporation. The expression of the target peptide induced by methanol was screened by means of Western hlotting, with the available MAb（Clone 6B6）. Highly expressive engineer strains were obtained. The production of recombinant H-FABP under induction was about 0.7 g/L, with an Mr of 14.5 kDa and recognized by a commercially available MAb （Clone 6B6）. The recombinant vector was successfully constructed. Following this, H-FABP was expressed in X-33, and it would become the source of the preparation of specific antibodies, to develop diagnostic kits.

Effects of 8-OHdG,H-FABP and CRP on the Development of Ischemic Cardiomyopathy

[Objectives]To analyze the relationship between serum 8-hydroxydeoxyguanosine(8-OHdG),heart fatty acid-binding protein(H-FABP),C-reactive protein(CRP)levels and clinical efficacy and short-term prognosis in patients with ischemic cardiomyopathy.[Methods]The clinical data of 100 patients with ischemic cardiomyopathy from October 2021 to November 2022 were retrospectively analyzed,and the serum levels of 8-OHdG,H-FABP and CRP were compared before and one week after treatment.The patients were followed up for 12 months after discharge,and the incidence of major adverse cardiovascular events(MACE)was counted during the follow-up period.Univariate and multivariate Logistic regression analysis were used to analyze the prognostic factors of patients with ischemic cardiomyopathy in the near future,and the predictive value of serum 8-OHdG,H-FABP and CRP levels for the prognosis of patients was evaluated by ROC curve.[Results]After 1 week of treatment,the serum levels of 8-OHdG,H-FABP and CRP in patients with ischemic cardiomyopathy were significantly lower than those before treatment(P<0.05).During the follow-up period,34 patients developed MACE;the serum levels of 8-OHdG,H-FABP and CRP in the MACE group were higher than those in the non-MACE group,and the differences were statistically significant(P<0.05).Multivariate Logistic regression analysis showed that 8-OHdG,H-FABP and CRP were the risk factors of MACE in patients with ischemic cardiomyopathy(P<0.05).ROC curve analysis showed that the combined prediction of 8-OHdG,H-FABP and CRP for MACE in patients with ischemic cardiomyopathy was higher than that of CRP,H-FABP and 8-OHdG alone(P<0.05).[Conclusions]8-OHdG,H-FABP and CRP are closely related to the clinical efficacy and short-term prognosis of patients with ischemic cardiomyopathy,and the detection of serum 8-OHdG,H-FABP and CRP levels can help to evaluate the clinical efficacy and short-term prognosis of patients with ischemic cardiomyopathy.