title: The effect of albumin fusion patterns on the production and bioactivity of the somatostatin-14 fusion protein in Pichia pastoris.
abstract: Somatostatin is a natural inhibitor of growth hormone, and its analogues are clinically used for the therapy of acromegaly, gigantism, thyrotropinoma, and other carcinoid syndrome. However, natural somatostatin is limited for clinical usage because of its short half-life in vivo. Albumin fusion technology was used to construct long-acting fusion proteins, and Pichia pastoris was used as an expression system. Three fusion proteins, (somatostatin (SS)14)2-human serum albumin (HSA), (SS14)3-HSA, and HSA-(SS14)3, were constructed with different fusion copies of somatostatin-14 and fusion orientations. The expression level of (SS14)3-HSA and HSA-(SS14)3 was much lower than (SS14)2-HSA due to the additional fusion of the somatostatin-14 molecule. Matrix-assisted laser desorption ionization-time-of-flight mass spectrometry revealed that severe degradation occurred in the fermentation process. Similar to the standard of somatostatin-14, all three fusion proteins were able to inhibit growth hormone secretion in the blood, with (SS14)2-HSA being the most effective one. On the whole, (SS14)2-HSA was the most effective protein in both production level and bioactivity, and increasing the number of small protein copies fused to HSA may not be a suitable method to improve the protein bioactivity.
authors.affiliation: Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, QianRong Road No. 20, Wuxi, Jiangsu 214063, China.
authors.forename: Yuedi
authors.initials: Y
authors.lastname: Ding
authors.forename: Jun
authors.initials: J
authors.lastname: Fan
authors.forename: Wenxin
authors.initials: W
authors.lastname: Li
authors.forename: Runlin
authors.initials: R
authors.lastname: Yang
authors.forename: Ying
authors.initials: Y
authors.lastname: Peng
authors.forename: Lili
authors.initials: L
authors.lastname: Deng
authors.forename: Yu
authors.initials: Y
authors.lastname: Wu
authors.forename: Qiang
authors.initials: Q
authors.lastname: Fu
mesh_terms: D004926:Escherichia coli / Q000502:physiology*; D006801:Humans; D010843:Pichia / Q000502:physiology*; D015202:Protein Engineering / Q000379:methods*; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis* / Q000737:chemistry*; D012709:Serum Albumin / Q000235:genetics / Q000378:metabolism*; D013004:Somatostatin / Q000096:biosynthesis* / Q000235:genetics / Q000302:isolation & purification; D014162:Transfection / Q000379:methods
chemical_list: D011993:Recombinant Fusion Proteins; D012709:Serum Albumin; D013004:Somatostatin