文献

BP4118：重组人IgG1 Fc-N297A蛋白，体内实验级（In Vivo Grade Recombinant Human IgG1 Fc-D297A Protein）

重组人 IgG1 Fc 蛋白（hIgG1 Fc）包含重链恒定区的 CH2 与 CH3 结构域。绝大多数治疗性抗体药物以及 Fc 融合蛋白均携带天然人 IgG1 Fc 区，或是经过工程改造的突变体。在各类体外及体内实验中，重组人 IgG1 Fc 蛋白可作为 hIgG1 抗体与 hIgG1 Fc 融合蛋白的同型对照。

对 IgG Fc 序列（包括糖基化位点）的改造可用于调控 Fc 功能。即便是单一位点突变，也可能同时产生 Fc 结合能力增强与减弱的双重效应。为改变 IgG1 抗体或 IgG1 Fc 融合蛋白的免疫特性，研究人员对其 Fc 区引入下述突变，通过 Fc 与宿主蛋白发生相互作用实现功能改造。

人IgG1 Fc-N297A蛋白部分参考文献：

1.A Single Immunization with Spike‑Functionalized Ferritin Vaccines Elicits Neutralizing Antibody Responses against SARS‑CoV‑2 in Mice.
Powell, A. E., et al. ACS Cent Sci. 2021 Jan;7(1):183‑199. PMID: 33527087
“For purified mAbs and ACE2‑Fc, Direct‑Blot HRP antihuman IgG1 Fc antibody was added at a 1:10,000 dilution in diluent buffer for 1 h at room temperature. …ACE2 binding was measured with Direct‑Blot HRP antihuman IgG1 Fc at a 1:10,000 dilution, and blocking was quantified as the decrease in observed ACE2 binding as a function of serum dilution. …The development of a safe and effective SARS‑CoV‑2 vaccine is a public health priority. …Ferritin is an attractive nanoparticle platform for production of vaccines, and ferritin‑based vaccines have been investigated in humans in two separate clinical trials. …Additionally, a single dose of SΔC‑Fer elicited significantly higher neutralizing responses as compared to immunization with the spike receptor binding domain (RBD) monomer or spike ectodomain trimer alone.”

2.Development of a novel, fully human, anti‑PCSK9 antibody with potent hypolipidemic activity by utilizing phage display‑based strategy.
Xu, M., et al. EBioMedicine. 2021 Mar;65:103250. PMID: 33647772
“Thereafter, it was transformed to a full‑length Fc‑silenced anti‑PCSK9 antibody FAP2M21 by fusing to a modified human IgG1 Fc fragment with L234A/L235A/N297G mutations and C‑terminal lysine deletion, thus eliminating its immune effector functions and mitigating mAb heterogeneity. …Thereafter, considering the full‑length IgG mAb being the most appropriate format for clinical applications because of its long half‑life, high stability and bivalent binding property [64,65], we further constructed the full‑length Fc‑silenced anti‑PCSK9 antibodies by fusing two anti‑PCSK9 scFv variants (AP2M18 and AP2M21) to a modified human IgG1 Fc fragment with L234A/L235A/N297G mutations and C‑terminal lysine deletion, thereby eliminating the immune effector functions and mitigating the potential mAb heterogeneity. …In summary, we generate a novel, fully human, anti‑PCSK9 IgG1 mAb FAP2M21 with a high affinity to PCSK9 and an extremely slow dissociation rate by screening a fully human scFv phage display library, in vitro affinity maturation as well as fusing with a modified human IgG1 Fc fragment. …Proprotein convertase subtilase/kexin type 9 (PCSK9) regulates serum LDL cholesterol (LDL‑C) levels by facilitating the degradation of the LDL receptor (LDLR) and is an attractive therapeutic target for hypercholesterolemia intervention. …A potent single‑chain variable fragment (scFv) named AP2M21 was obtained by screening a fully human scFv phage display library with hPCSK9, and performing two in vitro affinity maturation processes including CDR‑targeted tailored mutagenesis and cross‑cloning.”

3.A Novel Splice Variant of Human TGF‑β Type II Receptor Encodes a Soluble Protein and Its Fc‑Tagged Version Prevents Liver Fibrosis in vivo.
Bertolio, M. S., et al. Front Cell Dev Biol. 2021 Sep;9:690397. PMID: 34568316
“TβRII‑SE and human IgG1 Fc domain were fused in frame in a lentiviral vector (Lv) for further characterization. …Either coTβRII‑SE/Fc or TβRII‑EC was ligated to the human IgG1 Fc coding sequence and cloned into a self‑inactivating (SIN) bicistronic lentiviral vectors making Lv.TβRII‑SE/Fc and Lv.TβRII‑Fc, respectively. …The human IgG1 Fc coding sequence was obtained by RT‑PCR from peripheral blood leucocyte mRNA using specific oligonucleotides as primers (forward: 5′‑AGATCTGACAAAACTCACACATGC‑3′ and reverse: 5′‑GATATCTTTACCCGGAGACAGG‑3′), containing a BglII recognition site (forward primer) and an EcoRV site (reverse primer). …Transforming growth factor‑β (TGF‑β) is a multifunctional cytokine involved in critical processes, including immune regulation and wound healing together with cell proliferation, maturation, and differentiation. …Ligand binding to the receptor ectodomains induces conformational changes at the ligand–receptor interface, bringing their cytoplasmic domains closer.”