Nejvíce citovaný článek - PubMed ID 24819248
Insight into the structural and biological relevance of the T/R transition of the N-terminus of the B-chain in human insulin
OBJECTIVE: The insulin/IGF superfamily is conserved across vertebrates and invertebrates. Our team has identified five viruses containing genes encoding viral insulin/IGF-1 like peptides (VILPs) closely resembling human insulin and IGF-1. This study aims to characterize the impact of Mandarin fish ranavirus (MFRV) and Lymphocystis disease virus-Sa (LCDV-Sa) VILPs on the insulin/IGF system for the first time. METHODS: We chemically synthesized single chain (sc, IGF-1 like) and double chain (dc, insulin like) forms of MFRV and LCDV-Sa VILPs. Using cell lines overexpressing either human insulin receptor isoform A (IR-A), isoform B (IR-B) or IGF-1 receptor (IGF1R), and AML12 murine hepatocytes, we characterized receptor binding, insulin/IGF signaling. We further characterized the VILPs' effects of proliferation and IGF1R and IR gene expression, and compared them to native ligands. Additionally, we performed insulin tolerance test in CB57BL/6 J mice to examine in vivo effects of VILPs on blood glucose levels. Finally, we employed cryo-electron microscopy (cryoEM) to analyze the structure of scMFRV-VILP in complex with the IGF1R ectodomain. RESULTS: VILPs can bind to human IR and IGF1R, stimulate receptor autophosphorylation and downstream signaling pathways. Notably, scMFRV-VILP exhibited a particularly strong affinity for IGF1R, with a mere 10-fold decrease compared to human IGF-1. At high concentrations, scMFRV-VILP selectively reduced IGF-1 stimulated IGF1R autophosphorylation and Erk phosphorylation (Ras/MAPK pathway), while leaving Akt phosphorylation (PI3K/Akt pathway) unaffected, indicating a potential biased inhibitory function. Prolonged exposure to MFRV-VILP led to a significant decrease in IGF1R gene expression in IGF1R overexpressing cells and AML12 hepatocytes. Furthermore, insulin tolerance test revealed scMFRV-VILP's sustained glucose-lowering effect compared to insulin and IGF-1. Finally, cryo-EM analysis revealed that scMFRV-VILP engages with IGF1R in a manner closely resembling IGF-1 binding, resulting in a highly analogous structure. CONCLUSIONS: This study introduces MFRV and LCDV-Sa VILPs as novel members of the insulin/IGF superfamily. Particularly, scMFRV-VILP exhibits a biased inhibitory effect on IGF1R signaling at high concentrations, selectively inhibiting IGF-1 stimulated IGF1R autophosphorylation and Erk phosphorylation, without affecting Akt phosphorylation. In addition, MFRV-VILP specifically regulates IGF-1R gene expression and IGF1R protein levels without affecting IR. CryoEM analysis confirms that scMFRV-VILP' binding to IGF1R is mirroring the interaction pattern observed with IGF-1. These findings offer valuable insights into IGF1R action and inhibition, suggesting potential applications in development of IGF1R specific inhibitors and advancing long-lasting insulins.
- Klíčová slova
- Biased signaling, IGF-1, IGF1 receptor, IGF1 receptor inhibition, Insulin, Iridoviridae, Viral insulin/IGF-1 like peptides (VILPs),
- MeSH
- elektronová kryomikroskopie MeSH
- exprese genu MeSH
- fosfatidylinositol-3-kinasy metabolismus MeSH
- fosforylace MeSH
- insulinu podobný růstový faktor I * genetika metabolismus MeSH
- inzulin metabolismus MeSH
- lidé MeSH
- myši MeSH
- protein - isoformy metabolismus MeSH
- protoonkogenní proteiny c-akt metabolismus MeSH
- receptor IGF typ 1 * genetika metabolismus MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- fosfatidylinositol-3-kinasy MeSH
- IGF1R protein, human MeSH Prohlížeč
- insulinu podobný růstový faktor I * MeSH
- inzulin MeSH
- protein - isoformy MeSH
- protoonkogenní proteiny c-akt MeSH
- receptor IGF typ 1 * MeSH
Insulin is stored in vivo inside the pancreatic β-cell insulin secretory granules. In vitro studies have led to an assumption that high insulin and Zn2+ concentrations inside the pancreatic β-cell insulin secretory granules should promote insulin crystalline state in the form of Zn2+-stabilized hexamers. Electron microscopic images of thin sections of the pancreatic β-cells often show a dense, regular pattern core, suggesting the presence of insulin crystals. However, the structural features of the storage forms of insulin in native preparations of secretory granules are unknown, because of their small size, fragile character and difficult handling. We isolated and investigated the secretory granules from MIN6 cells under near-native conditions, using cryo-electron microscopic (Cryo-EM) techniques. The analysis of these data from multiple intra-granular crystals revealed two different rhomboidal crystal lattices. The minor lattice has unit cell parameters (a ≃ b ≃ 84.0 Å, c ≃ 35.2 Å), similar to in vitro crystallized human 4Zn2+-insulin hexamer, whereas the largely prevalent unit cell has more than double c-axis (a ≃ b ≃ c ≃ 96.5 Å) that probably corresponds to two or three insulin hexamers in the asymmetric unit. Our experimental data show that insulin can be present in pancreatic MIN6 cell granules in a microcrystalline form, probably consisting of 4Zn2+-hexamers of this hormone.
- Klíčová slova
- crystallization in vivo, electron microscopy, insulin secretion, peptide hormone, secretory granules, subcellular vesicle,
- MeSH
- beta-buňky * MeSH
- elektronová mikroskopie MeSH
- inzulin MeSH
- Langerhansovy ostrůvky * MeSH
- lidé MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- inzulin MeSH
OBJECTIVE: Members of the insulin/insulin-like growth factor (IGF) superfamily are well conserved across the evolutionary tree. We recently showed that four viruses in the Iridoviridae family possess genes that encode proteins highly homologous to human insulin/IGF-1. Using chemically synthesized single-chain (sc), i.e., IGF-1-like, forms of the viral insulin/IGF-1-like peptides (VILPs), we previously showed that they can stimulate human receptors. Because these peptides possess potential cleavage sites to form double chain (dc), i.e., more insulin-like, VILPs, in this study, we have characterized dc forms of VILPs for Grouper iridovirus (GIV), Singapore grouper iridovirus (SGIV) and Lymphocystis disease virus-1 (LCDV-1) for the first time. METHODS: The dcVILPs were chemically synthesized. Using murine fibroblast cell lines overexpressing insulin receptor (IR-A or IR-B) or IGF1R, we first determined the binding affinity of dcVILPs to the receptors and characterized post-receptor signaling. Further, we used C57BL/6J mice to study the effect of dcVILPs on lowering blood glucose. We designed a 3-h dcVILP in vivo infusion experiment to determine the glucose uptake in different tissues. RESULTS: GIV and SGIV dcVILPs bind to both isoforms of human insulin receptor (IR-A and IR-B) and to the IGF1R, and for the latter, show higher affinity than human insulin. These dcVILPs stimulate IR and IGF1R phosphorylation and post-receptor signaling in vitro and in vivo. Both GIV and SGIV dcVILPs stimulate glucose uptake in mice. In vivo infusion experiments revealed that while insulin (0.015 nmol/kg/min) and GIV dcVILP (0.75 nmol/kg/min) stimulated a comparable glucose uptake in heart and skeletal muscle and brown adipose tissue, GIV dcVILP stimulated 2-fold higher glucose uptake in white adipose tissue (WAT) compared to insulin. This was associated with increased Akt phosphorylation and glucose transporter type 4 (GLUT4) gene expression compared to insulin in WAT. CONCLUSIONS: Our results show that GIV and SGIV dcVILPs are active members of the insulin superfamily with unique characteristics. Elucidating the mechanism of tissue specificity for GIV dcVILP will help us to better understand insulin action, design new analogs that specifically target the tissues and provide new insights into their potential role in disease.
- Klíčová slova
- Adipose tissue, GLUT4, Glucose metabolism, IGF-1, Insulin, VILPs, Viral insulin, Viral mimicry,
- MeSH
- bílá tuková tkáň metabolismus MeSH
- buněčné linie MeSH
- CD antigeny MeSH
- fosforylace MeSH
- glukosa metabolismus MeSH
- hnědá tuková tkáň metabolismus MeSH
- insulinu podobný růstový faktor I metabolismus MeSH
- inzulin genetika metabolismus MeSH
- inzuliny metabolismus MeSH
- Iridovirus genetika MeSH
- iridoviry genetika MeSH
- lidé MeSH
- myši inbrední C57BL MeSH
- myši MeSH
- receptor IGF typ 1 genetika metabolismus MeSH
- receptor inzulinu metabolismus MeSH
- signální transdukce MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
- Názvy látek
- CD antigeny MeSH
- glukosa MeSH
- IGF1 protein, human MeSH Prohlížeč
- IGF1R protein, human MeSH Prohlížeč
- Igf1r protein, mouse MeSH Prohlížeč
- INSR protein, human MeSH Prohlížeč
- insulinu podobný růstový faktor I MeSH
- inzulin MeSH
- inzuliny MeSH
- receptor IGF typ 1 MeSH
- receptor inzulinu MeSH
Insulin is produced and stored inside the pancreatic β-cell secretory granules, where it is assumed to form Zn2+-stabilized oligomers. However, the actual storage forms of this hormone and the impact of zinc ions on insulin production in vivo are not known. Our initial X-ray fluorescence experiment on granules from native Langerhans islets and insulinoma-derived INS-1E cells revealed a considerable difference in the zinc content. This led our further investigation to evaluate the impact of the intra-granular Zn2+ levels on the production and storage of insulin in different model β-cells. Here, we systematically compared zinc and insulin contents in the permanent INS-1E and BRIN-BD11 β-cells and in the native rat pancreatic islets by flow cytometry, confocal microscopy, immunoblotting, specific messenger RNA (mRNA) and total insulin analysis. These studies revealed an impaired insulin production in the permanent β-cell lines with the diminished intracellular zinc content. The drop in insulin and Zn2+ levels was paralleled by a lower expression of ZnT8 zinc transporter mRNA and hampered proinsulin processing/folding in both permanent cell lines. To summarize, we showed that the disruption of zinc homeostasis in the model β-cells correlated with their impaired insulin and ZnT8 production. This indicates a need for in-depth fundamental research about the role of zinc in insulin production and storage.
- Klíčová slova
- insulin, pancreatic islets, proinsulin, zinc ions, znt8, β-cells,
- MeSH
- beta-buňky metabolismus ultrastruktura MeSH
- chemická frakcionace MeSH
- cytoplazmatická granula metabolismus MeSH
- exprese genu * MeSH
- glukosa metabolismus MeSH
- inzulin genetika metabolismus MeSH
- krysa rodu Rattus MeSH
- Langerhansovy ostrůvky metabolismus MeSH
- messenger RNA genetika metabolismus MeSH
- průtoková cytometrie metody MeSH
- zinek metabolismus MeSH
- zinkový transportér 8 MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- glukosa MeSH
- inzulin MeSH
- messenger RNA MeSH
- Slc30a8 protein, rat MeSH Prohlížeč
- zinek MeSH
- zinkový transportér 8 MeSH
Insulin-like growth factors 2 and 1 (IGF2 and IGF1) and insulin are closely related hormones that are responsible for the regulation of metabolic homeostasis, development and growth of the organism. Physiological functions of insulin and IGF1 are relatively well-studied, but information about the role of IGF2 in the body is still sparse. Recent discoveries called attention to emerging functions of IGF2 in the brain, where it could be involved in processes of learning and memory consolidation. It was also proposed that these functions could be mediated by the receptor for IGF2 (IGF2R). Nevertheless, little is known about the mechanism of signal transduction through this receptor. Here we produced His-tagged domain 11 (D11), an IGF2-binding element of IGF2R; we immobilized it on the solid support through a well-defined sandwich, consisting of neutravidin, biotin and synthetic anti-His-tag antibodies. Next, we prepared specifically radiolabeled [125I]-monoiodotyrosyl-Tyr2-IGF2 and optimized a sensitive and robust competitive radioligand binding assay for determination of the nanomolar binding affinities of hormones for D11 of IGF2. The assay will be helpful for the characterization of new IGF2 mutants to study the functions of IGF2R and the development of new compounds for the treatment of neurological disorders.
- MeSH
- insulinu podobný růstový faktor I metabolismus MeSH
- insulinu podobný růstový faktor II metabolismus MeSH
- kompetitivní vazba MeSH
- kultivované buňky MeSH
- lidé MeSH
- radioizotopy jodu MeSH
- radioligandová zkouška metody MeSH
- receptor IGF typ 2 imunologie ultrastruktura MeSH
- signální transdukce MeSH
- vazba proteinů MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- IGF1 protein, human MeSH Prohlížeč
- IGF2 protein, human MeSH Prohlížeč
- IGF2R protein, human MeSH Prohlížeč
- insulinu podobný růstový faktor I MeSH
- insulinu podobný růstový faktor II MeSH
- Iodine-125 MeSH Prohlížeč
- radioizotopy jodu MeSH
- receptor IGF typ 2 MeSH
Information on how insulin and insulin-like growth factors 1 and 2 (IGF-1 and -2) activate insulin receptors (IR-A and -B) and the IGF-1 receptor (IGF-1R) is crucial for understanding the difference in the biological activities of these peptide hormones. Cryo-EM studies have revealed that insulin uses its binding sites 1 and 2 to interact with IR-A and have identified several critical residues in binding site 2. However, mutagenesis studies suggest that Ile-A10, Ser-A12, Leu-A13, and Glu-A17 also belong to insulin's site 2. Here, to resolve this discrepancy, we mutated these insulin residues and the equivalent residues in IGFs. Our findings revealed that equivalent mutations in the hormones can result in differential biological effects and that these effects can be receptor-specific. We noted that the insulin positions A10 and A17 are important for its binding to IR-A and IR-B and IGF-1R and that A13 is important only for IR-A and IR-B binding. The IGF-1/IGF-2 positions 51/50 and 54/53 did not appear to play critical roles in receptor binding, but mutations at IGF-1 position 58 and IGF-2 position 57 affected the binding. We propose that IGF-1 Glu-58 interacts with IGF-1R Arg-704 and belongs to IGF-1 site 1, a finding supported by the NMR structure of the less active Asp-58-IGF-1 variant. Computational analyses indicated that the aforementioned mutations can affect internal insulin dynamics and inhibit adoption of a receptor-bound conformation, important for binding to receptor site 1. We provide a molecular model and alternative hypotheses for how the mutated insulin residues affect activity.
- Klíčová slova
- NMR structure, complex, hormone analog, insulin, insulin-like growth factor (IGF), molecular dynamics, mutagenesis, peptide hormone, receptor autophosphorylation, receptor binding, receptor tyrosine kinase, structural biology, structure-function,
- MeSH
- insulinu podobný růstový faktor I chemie genetika MeSH
- insulinu podobný růstový faktor II chemie genetika MeSH
- inzulin analogy a deriváty chemická syntéza chemie genetika MeSH
- lidé MeSH
- mnohočetné abnormality genetika MeSH
- mutace genetika MeSH
- nukleární magnetická rezonance biomolekulární MeSH
- poruchy růstu genetika MeSH
- proteinové domény genetika MeSH
- receptor IGF typ 1 chemie genetika MeSH
- receptor inzulinu chemie genetika MeSH
- sekvence aminokyselin genetika MeSH
- vazba proteinů genetika MeSH
- vazebná místa genetika MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- IGF1R protein, human MeSH Prohlížeč
- IGF2 protein, human MeSH Prohlížeč
- insulinu podobný růstový faktor I MeSH
- insulinu podobný růstový faktor II MeSH
- inzulin MeSH
- receptor IGF typ 1 MeSH
- receptor inzulinu MeSH
Insulin and insulin-like growth factors I and II are closely related protein hormones. Their distinct evolution has resulted in different yet overlapping biological functions with insulin becoming a key regulator of metabolism, whereas insulin-like growth factors (IGF)-I/II are major growth factors. Insulin and IGFs cross-bind with different affinities to closely related insulin receptor isoforms A and B (IR-A and IR-B) and insulin-like growth factor type I receptor (IGF-1R). Identification of structural determinants in IGFs and insulin that trigger their specific signaling pathways is of increasing importance in designing receptor-specific analogs with potential therapeutic applications. Here, we developed a straightforward protocol for production of recombinant IGF-II and prepared six IGF-II analogs with IGF-I-like mutations. All modified molecules exhibit significantly reduced affinity toward IR-A, particularly the analogs with a Pro-Gln insertion in the C-domain. Moreover, one of the analogs has enhanced binding affinity for IGF-1R due to a synergistic effect of the Pro-Gln insertion and S29N point mutation. Consequently, this analog has almost a 10-fold higher IGF-1R/IR-A binding specificity in comparison with native IGF-II. The established IGF-II purification protocol allowed for cost-effective isotope labeling required for a detailed NMR structural characterization of IGF-II analogs that revealed a link between the altered binding behavior of selected analogs and conformational rearrangement of their C-domains.
- Klíčová slova
- insulin, insulin receptor, insulin-like growth factor (IGF), nuclear magnetic resonance (NMR), structural biology, structure-function,
- MeSH
- CD antigeny chemie genetika metabolismus MeSH
- insulinu podobný růstový faktor II chemie genetika metabolismus MeSH
- lidé MeSH
- missense mutace MeSH
- protein - isoformy chemie genetika metabolismus MeSH
- proteinové domény MeSH
- receptor IGF typ 1 chemie genetika metabolismus MeSH
- receptor inzulinu chemie genetika metabolismus MeSH
- rekombinantní proteiny chemie genetika metabolismus MeSH
- substituce aminokyselin MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- CD antigeny MeSH
- IGF2 protein, human MeSH Prohlížeč
- INSR protein, human MeSH Prohlížeč
- insulinu podobný růstový faktor II MeSH
- protein - isoformy MeSH
- receptor IGF typ 1 MeSH
- receptor inzulinu MeSH
- rekombinantní proteiny MeSH
Insulin is a key hormone of human metabolism with major therapeutic importance for both types of diabetes. New insulin analogues with more physiological profiles and better glycemic control are needed, especially analogues that preferentially bind to the metabolic B-isoform of insulin receptor (IR-B). Here, we aimed to stabilize and modulate the receptor-compatible conformation of insulin by covalent intra-chain crosslinking within its B22-B30 segment, using the Cu(I)-catalyzed Huisgen 1,3-dipolar cycloaddition reaction of azides and alkynes. This approach resulted in 14 new, systematically crosslinked insulin analogues whose structures and functions were extensively characterized and correlated. One of the analogues, containing a B26-B29 triazole bridge, was highly active in binding to both IR isoforms, with a significant preference for IR-B. Our results demonstrate the potential of chemistry-driven modulation of insulin function, also shedding new light on the functional importance of hormone's B-chain C-terminus for its IR-B specificity.
- MeSH
- alkyny chemie MeSH
- azidy chemie MeSH
- cykloadiční reakce MeSH
- inzulin chemie metabolismus MeSH
- konformace proteinů MeSH
- lidé MeSH
- molekulární modely MeSH
- protein - isoformy MeSH
- receptor IGF typ 1 chemie metabolismus MeSH
- receptor inzulinu chemie metabolismus MeSH
- stabilita proteinů MeSH
- vazba proteinů MeSH
- vztahy mezi strukturou a aktivitou MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- alkyny MeSH
- azidy MeSH
- inzulin MeSH
- protein - isoformy MeSH
- receptor IGF typ 1 MeSH
- receptor inzulinu MeSH
The insulin gene mutation c.137G>A (R46Q), which changes an arginine at the B22 position of the mature hormone to glutamine, causes the monogenic diabetes variant maturity-onset diabetes of the young (MODY). In MODY patients, this mutation is heterozygous, and both mutant and wild-type (WT) human insulin are produced simultaneously. However, the patients often depend on administration of exogenous insulin. In this study, we chemically synthesized the MODY mutant [GlnB22]-insulin and characterized its biological and structural properties. The chemical synthesis of this insulin analogue revealed that its folding ability is severely impaired. In vitro and in vivo tests showed that its binding affinity and biological activity are reduced (both approximately 20% that of human insulin). Comparison of the solution structure of [GlnB22]-insulin with the solution structure of native human insulin revealed that the most significant structural effect of the mutation is distortion of the B20-B23 β-turn, leading to liberation of the B chain C-terminus from the protein core. The distortion of the B20-B23 β-turn is caused by the extended conformational freedom of the GlnB22 side chain, which is no longer anchored in a hydrogen bonding network like the native ArgB22. The partially disordered [GlnB22]-insulin structure appears to be one reason for the reduced binding potency of this mutant and may also be responsible for its low folding efficiency in vivo. The altered orientation and flexibility of the B20-B23 β-turn may interfere with the formation of disulfide bonds in proinsulin bearing the R46Q (GlnB22) mutation. This may also have a negative effect on the WT proinsulin simultaneously biosynthesized in β-cells and therefore play a major role in the development of MODY in patients producing [GlnB22]-insulin.
- MeSH
- diabetes mellitus 2. typu farmakoterapie genetika metabolismus MeSH
- glutamin genetika MeSH
- inzulin chemie genetika metabolismus terapeutické užití MeSH
- inzulinová rezistence MeSH
- kultivované buňky MeSH
- lidé MeSH
- missense mutace * MeSH
- molekulární sekvence - údaje MeSH
- myši inbrední C57BL MeSH
- myši MeSH
- sekvence aminokyselin MeSH
- vazba proteinů MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- glutamin MeSH
- inzulin MeSH
The structural characterization of the insulin-insulin receptor (IR) interaction still lacks the conformation of the crucial B21-B30 insulin region, which must be different from that in its storage forms to ensure effective receptor binding. Here, it is shown that insulin analogues modified by natural amino acids at the TyrB26 site can represent an active form of this hormone. In particular, [AsnB26]-insulin and [GlyB26]-insulin attain a B26-turn-like conformation that differs from that in all known structures of the native hormone. It also matches the receptor interface, avoiding substantial steric clashes. This indicates that insulin may attain a B26-turn-like conformation upon IR binding. Moreover, there is an unexpected, but significant, binding specificity of the AsnB26 mutant for predominantly the metabolic B isoform of the receptor. As it is correlated with the B26 bend of the B-chain of the hormone, the structures of AsnB26 analogues may provide the first structural insight into the structural origins of differential insulin signalling through insulin receptor A and B isoforms.
- Klíčová slova
- active conformation, complex, insulin, insulin receptor, isothermal titration microcalorimetry, molecular dynamics,
- MeSH
- fenylalanin MeSH
- fibroblasty metabolismus MeSH
- inzulin analogy a deriváty chemie genetika metabolismus MeSH
- konformace proteinů MeSH
- krystalografie rentgenová MeSH
- kultivované buňky MeSH
- lidé MeSH
- lymfocyty metabolismus MeSH
- molekulární modely MeSH
- mutace MeSH
- myši knockoutované MeSH
- myši MeSH
- potkani Wistar MeSH
- receptor inzulinu chemie metabolismus MeSH
- substituce aminokyselin MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- fenylalanin MeSH
- inzulin MeSH
- receptor inzulinu MeSH