S H Nakagawa's research while affiliated with University of Chicago and other places

Publications (10)

Article
To evaluate more thoroughly the importance of main-chain structure and flexibility in ligand interactions with the insulin receptor, we undertook to synthesize analogues with reduced peptide bonds in the COOH-terminal B chain domain of the hormone (a stable, but adjustable beta-strand region). By use of solid-phase, solution-phase and semisynthetic...
Article
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We have examined, by use of a hybrid insulin/insulin-like growth factor-I analog and chimeric insulin/type I insulin-like growth factor receptors, the interplay between ligand and receptor structure in determining the affinity and specificity of hormone-receptor interactions in the insulin and insulin-like growth factor-I systems. Our findings, obt...
Article
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By the chemical synthesis of modified insulin B chains and the combination of the synthetic B chains with natural insulin A chains, we have prepared insulin analogs with natural and unnatural amino acid replacements of invariant residue LeuB6. Analogs have been investigated by reference to their potencies for interaction with the insulin receptor (...
Article
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By use of isolated canine hepatocytes and insulin analogs prepared by trypsin-catalyzed semisynthesis, we have investigated the importance of the aromatic triplet PheB24-PheB25-TyrB26 of the COOH-terminal B-chain domain of insulin in directing the affinity of insulin-receptor interactions. Analysis of the receptor binding potencies of analogs beari...
Article
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The conformational stability and flexibility of insulin containing a cross-link between the alpha-amino group of the A-chain to the epsilon-amino group of Lys29 of the B-chain was examined. The cross-link varied in length from 2 to 12 carbon atoms. The conformational stability was determined by guanidine hydrochloride-induced equilibrium denaturati...
Article
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We have prepared by semisynthetic methods a two-chain insulin/insulin-like growth factor I hybrid that contains a synthetic peptide related to residues 22-41 of insulin-like growth factor I linked via peptide bond to ArgB22 of des-octapeptide-(B23-B30)-insulin and have applied the analog to the analysis of ligand interactions with the type I insuli...
Article
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We have evaluated, by use of isolated canine hepatocytes, the importance of intramolecular hormone cross-linking (and of concomitant changes in molecular flexibility) to the interaction of insulin with its plasma membrane receptor. Cross-linked hormone analogs were prepared by reacting porcine insulin, N alpha A1-t-butyloxycarbonyl insulin or N alp...
Article
Previous studies have suggested that the COOH-terminal pentapeptide of the insulin B-chain can play a negative role in ligand-receptor interactions involving insulin analogs having amino acid replacements at position B25 (Nakagawa, S. H., and Tager, H. S. (1986) J. Biol. Chem. 261, 7332-7341). We undertook by the current investigations to identify...
Article
Full-text available
Previous studies have suggested that the COOH-terminal pentapeptide of the insulin B-chain can play a negative role in ligand-receptor interactions involving insulin analogs having amino acid replacements at position B25 (Nakagawa, S. H., and Tager, H. S. (1986) J. Biol. Chem. 261, 7332-7341). We undertook by the current investigations to identify...
Article
Full-text available
To gain an understanding of the causes of decreased biological activity in insulins bearing amino acid substitutions at position B25 and the importance of the PheB25 side chain in directing hormone-receptor interactions, we have prepared a variety of insulin analogs and have studied both their interactions with isolated canine hepatocytes and their...

Citations

... On the other hand, the C-terminal b-strand area, PheB25 and TyrB26, in insulin is required to direct the insulin receptor [18][19][20][21][22]. When the 4-kDa peptide was compared to the active state of insulin, Leu27 and Phe28 of the 4-kDa peptide could occupy a similar place as PheB25 and TyrB26 of insulin (Fig. 7E,F). ...
... Several insulin derivatives or analogs were also reported, among them the single-chain insulin with a crosslink between the A1 and B29 residues was well-studied experimentally (152)(153)(154)(155). The reported single-chain insulin was biologically inactive Shown in tabulated data are PDB codes (where known; n/a, not available) and simulation conditions including water models SPC, TIP3P, TIP4P, and their variants. ...
... HSA binding was strengthened by further lengthening the dicarboxylic adduct at Lys B29 (C-20 diacid linked through a 2xOEG-γ Glu linker; Fig. 3) (92). IR binding was decreased by paired aromatic substitutions in the B chain (Tyr B16 His and Phe B25 His (93)(94)(95)(96), which also augments stability toward proteolysis (97)); these side chains pack at or near the hormone-receptor interface (Fig. 3A-C). Thermodynamic stability is augmented by a "reverse hydrophobic" substitution at the A-chain surface (Tyr A14 Glu). ...
... Another mutation affecting C96, p.C96Y, has been studied in Akita mice (carrying the insulin 2 Ins2 +/C96Y mutation) to improve understanding of this mutation in diabetes pathogenesis, for example, misfolded proinsulin, ER stress, b-cell apoptosis or proliferation defect, or diabetes phenotype heterogeneity between male and female Akita mice (34)(35)(36)(37)(38)(39). The residue L30 (B6) could be involved in orienting the Nterminal region, maintaining local structure in the vicinity of the B7-A7 disulfide, or making contact with a receptor (40). The modeling of insulin also indicated L30 (B6) interacts with C95 (A6) via a hydrogen bond (distance = 2.06 Å) and the mutation p.L30V increases B6-A6 distance to 2.74 Å (Supplementary Figure 3). ...
... However, such an adverse effect is not observed for mini-Ins, which has 20-fold weaker affinity for IGF-1R compared to human insulin. Although DOI has a weak affinity toward hIR, it is also 100-fold weaker than human insulin in its binding to IGF-1R, suggesting that the C-terminal B-chain fragment is critical also for IGF-1R binding 30 . Mini-Ins therefore has the highest IR/IGF-1R binding ratio among all known insulin analogs 29,31 . ...
... Several insulin derivatives or analogs were also reported, among them the single-chain insulin with a crosslink between the A1 and B29 residues was well-studied experimentally (152)(153)(154)(155). The reported single-chain insulin was biologically inactive Shown in tabulated data are PDB codes (where known; n/a, not available) and simulation conditions including water models SPC, TIP3P, TIP4P, and their variants. ...
... Previous studies suggested that insulin fibrillation occurs through the formation of partially unfolded intermediate structures (14,44,45), but the exact events taking place during the nucleation stage have not been determined. This study focuses on the C-terminal region of human insulin B-chain, which serves as an interface site during the insulin dimerization (14,26), possesses high flexibility (46), and bears no significant contribution to the insulin binding to its receptor (40,47). To start with, the successful production of large quantities of highly homogeneous samples of the WT and mutant forms of insulin and its B-chain achieved in this study validated the, to our knowledge, novel method of recombinant insulin production we developed recently (30). ...
... HSA binding was strengthened by further lengthening the dicarboxylic adduct at Lys B29 (C-20 diacid linked through a 2xOEG-γ Glu linker; Fig. 3) (92). IR binding was decreased by paired aromatic substitutions in the B chain (Tyr B16 His and Phe B25 His (93)(94)(95)(96), which also augments stability toward proteolysis (97)); these side chains pack at or near the hormone-receptor interface (Fig. 3A-C). Thermodynamic stability is augmented by a "reverse hydrophobic" substitution at the A-chain surface (Tyr A14 Glu). ...
... The regions in the insulin molecule responsible for interaction with the insulin receptor are the Nterminus of the A chain, the C-terminal β-strand of the B-chain, the central α-helix of the B-chain, and the residues close to these regions [5][6][7][8][9]. Despite this large amount of information the active conformation of insulin is still unknown. ...
... This belief is based on a number of historical studies with radiolabeled insulin that were performed some 30 to 40 years ago (many in Denmark). [31][32][33] However, recent studies performed with swine and humans in which dyes 34 or insulin [35][36][37] were applied intradermally (ID) have shown much more rapid transfer of insulin via the lymphatic system than was previously reported. Additionally, multicompartment input models have been shown to have better fit to actual clinical PK data, implying parallel uptake pathways. ...