Abstract
The self-association of proteins is influenced by amino acid sequence, molecular conformation, and the presence of molecular additives. In the presence of phenolic additives, LysB28ProB29 insulin, in which the C-terminal prolyl and lysyl residues of wild-type human insulin have been inverted, can be crystallized into forms resembling those of wild-type insulins in which the protein exists as zinc-complexed hexamers organized into well-defined layers. We describe herein tapping-mode atomic force microscopy (TMAFM) studies of single crystals of rhombohedral (R3) LysB28ProB29 that reveal the influence of sequence variation on hexamer-hexamer association at the surface of actively growing crystals. Molecular scale lattice images of these crystals were acquired in situ under growth conditions, enabling simultaneous identification of the rhombohedral LysB28ProB29 crystal form, its orientation, and its dynamic growth characteristics. The ability to obtain crystallographic parameters on multiple crystal faces with TMAFM confirmed that bovine and porcine insulins grown under these conditions crystallized into the same space group as LysB28ProB29 (R3), enabling direct comparison of crystal growth behavior and the influence of sequence variation. Real-time TMAFM revealed hexamer vacancies on the (001) terraces of LysB28ProB29, and more rounded dislocation noses and larger terrace widths for actively growing screw dislocations compared to wild-type bovine and porcine insulin crystals under identical conditions. This behavior is consistent with weaker interhexamer attachment energies for LysB28ProB29 at active growth sites. Comparison of the single crystal x-ray structures of wild-type insulins and LysB28ProB29 suggests that differences in protein conformation at the hexamer-hexamer interface and accompanying changes in interhexamer bonding are responsible for this behavior. These studies demonstrate that subtle changes in molecular conformation due to a single sequence inversion in a region critical for insulin self-association can have a significant effect on the crystallization of proteins.
Full Text
The Full Text of this article is available as a PDF (720.3 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Bakaysa D. L., Radziuk J., Havel H. A., Brader M. L., Li S., Dodd S. W., Beals J. M., Pekar A. H., Brems D. N. Physicochemical basis for the rapid time-action of LysB28ProB29-insulin: dissociation of a protein-ligand complex. Protein Sci. 1996 Dec;5(12):2521–2531. doi: 10.1002/pro.5560051215. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Baker E. N., Blundell T. L., Cutfield J. F., Cutfield S. M., Dodson E. J., Dodson G. G., Hodgkin D. M., Hubbard R. E., Isaacs N. W., Reynolds C. D. The structure of 2Zn pig insulin crystals at 1.5 A resolution. Philos Trans R Soc Lond B Biol Sci. 1988 Jul 6;319(1195):369–456. doi: 10.1098/rstb.1988.0058. [DOI] [PubMed] [Google Scholar]
- Bernstein F. C., Koetzle T. F., Williams G. J., Meyer E. F., Jr, Brice M. D., Rodgers J. R., Kennard O., Shimanouchi T., Tasumi M. The Protein Data Bank: a computer-based archival file for macromolecular structures. J Mol Biol. 1977 May 25;112(3):535–542. doi: 10.1016/s0022-2836(77)80200-3. [DOI] [PubMed] [Google Scholar]
- Berson S. A., Yalow R. S. Insulin in blood and insulin antibodies. Am J Med. 1966 May;40(5):676–690. doi: 10.1016/0002-9343(66)90148-3. [DOI] [PubMed] [Google Scholar]
- Birnbaum D. T., Kilcomons M. A., DeFelippis M. R., Beals J. M. Assembly and dissociation of human insulin and LysB28ProB29-insulin hexamers: a comparison study. Pharm Res. 1997 Jan;14(1):25–36. doi: 10.1023/a:1012095115151. [DOI] [PubMed] [Google Scholar]
- Bohidar H. B., Geissler E. Static and dynamic light scattering from dilute insulin solutions. Biopolymers. 1984 Nov;23(11 Pt 2):2407–2417. doi: 10.1002/bip.360231119. [DOI] [PubMed] [Google Scholar]
- Brange J., Owens D. R., Kang S., Vølund A. Monomeric insulins and their experimental and clinical implications. Diabetes Care. 1990 Sep;13(9):923–954. doi: 10.2337/diacare.13.9.923. [DOI] [PubMed] [Google Scholar]
- Brems D. N., Alter L. A., Beckage M. J., Chance R. E., DiMarchi R. D., Green L. K., Long H. B., Pekar A. H., Shields J. E., Frank B. H. Altering the association properties of insulin by amino acid replacement. Protein Eng. 1992 Sep;5(6):527–533. doi: 10.1093/protein/5.6.527. [DOI] [PubMed] [Google Scholar]
- Brems D. N., Brown P. L., Bryant C., Chance R. E., Green L. K., Long H. B., Miller A. A., Millican R., Shields J. E., Frank B. H. Improved insulin stability through amino acid substitution. Protein Eng. 1992 Sep;5(6):519–525. doi: 10.1093/protein/5.6.519. [DOI] [PubMed] [Google Scholar]
- Ciszak E., Beals J. M., Frank B. H., Baker J. C., Carter N. D., Smith G. D. Role of C-terminal B-chain residues in insulin assembly: the structure of hexameric LysB28ProB29-human insulin. Structure. 1995 Jun 15;3(6):615–622. doi: 10.1016/s0969-2126(01)00195-2. [DOI] [PubMed] [Google Scholar]
- Ciszak E., Smith G. D. Crystallographic evidence for dual coordination around zinc in the T3R3 human insulin hexamer. Biochemistry. 1994 Feb 15;33(6):1512–1517. doi: 10.1021/bi00172a030. [DOI] [PubMed] [Google Scholar]
- Durbin S. D., Feher G. Studies of crystal growth mechanisms of proteins by electron microscopy. J Mol Biol. 1990 Apr 20;212(4):763–774. doi: 10.1016/0022-2836(90)90235-E. [DOI] [PubMed] [Google Scholar]
- Hillier A. C., Ward M. D. Atomic force microscopy of the electrochemical nucleation and growth of molecular crystals. Science. 1994 Mar 4;263(5151):1261–1264. doi: 10.1126/science.263.5151.1261. [DOI] [PubMed] [Google Scholar]
- Hollenberg M. D. Receptor triggering and receptor regulation: structure-activity relationships from the receptor's point of view. J Med Chem. 1990 May;33(5):1275–1281. doi: 10.1021/jm00167a001. [DOI] [PubMed] [Google Scholar]
- Howey D. C., Bowsher R. R., Brunelle R. L., Woodworth J. R. [Lys(B28), Pro(B29)]-human insulin. A rapidly absorbed analogue of human insulin. Diabetes. 1994 Mar;43(3):396–402. doi: 10.2337/diab.43.3.396. [DOI] [PubMed] [Google Scholar]
- Hvidt S. Insulin association in neutral solutions studied by light scattering. Biophys Chem. 1991 Feb;39(2):205–213. doi: 10.1016/0301-4622(91)85023-j. [DOI] [PubMed] [Google Scholar]
- Jeffrey P. D. Polymerization behavior of bovine zinc-insulin at neutral pH. Molecular weight of the subunit and the effect of glucose. Biochemistry. 1974 Oct 8;13(21):4441–4447. doi: 10.1021/bi00718a029. [DOI] [PubMed] [Google Scholar]
- Kaarsholm N. C., Ko H. C., Dunn M. F. Comparison of solution structural flexibility and zinc binding domains for insulin, proinsulin, and miniproinsulin. Biochemistry. 1989 May 16;28(10):4427–4435. doi: 10.1021/bi00436a046. [DOI] [PubMed] [Google Scholar]
- Konnert J. H., D'Antonio P., Ward K. B. Observation of growth steps, spiral dislocations and molecular packing on the surface of lysozyme crystals with the atomic force microscope. Acta Crystallogr D Biol Crystallogr. 1994 Jul 1;50(Pt 4):603–613. doi: 10.1107/S0907444994001988. [DOI] [PubMed] [Google Scholar]
- Land TA, Malkin AJ, Kuznetsov YG, McPherson A, De Yoreo JJ Mechanisms of protein crystal growth: An atomic force microscopy study of canavalin crystallization. Phys Rev Lett. 1995 Oct 2;75(14):2774–2777. doi: 10.1103/PhysRevLett.75.2774. [DOI] [PubMed] [Google Scholar]
- Malkin AJ, Land TA, Kuznetsov YG, McPherson A, DeYoreo JJ. Investigation of virus crystal growth mechanisms by in situ atomic force microscopy. Phys Rev Lett. 1995 Oct 2;75(14):2778–2781. doi: 10.1103/PhysRevLett.75.2778. [DOI] [PubMed] [Google Scholar]
- Milthorpe B. K., Nichol L. W., Jeffrey P. D. The polymerization pattern of zinc(II)-insulin at pH 7.0. Biochim Biophys Acta. 1977 Dec 20;495(2):195–202. doi: 10.1016/0005-2795(77)90376-2. [DOI] [PubMed] [Google Scholar]
- Ng J. D., Kuznetsov Y. G., Malkin A. J., Keith G., Giegé R., McPherson A. Visualization of RNA crystal growth by atomic force microscopy. Nucleic Acids Res. 1997 Jul 1;25(13):2582–2588. doi: 10.1093/nar/25.13.2582. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Pedersen J. S., Hansen S., Bauer R. The aggregation behavior of zinc-free insulin studied by small-angle neutron scattering. Eur Biophys J. 1994;22(6):379–389. doi: 10.1007/BF00180159. [DOI] [PubMed] [Google Scholar]
- Smith G. D., Swenson D. C., Dodson E. J., Dodson G. G., Reynolds C. D. Structural stability in the 4-zinc human insulin hexamer. Proc Natl Acad Sci U S A. 1984 Nov;81(22):7093–7097. doi: 10.1073/pnas.81.22.7093. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Yip C. M., Ward M. D. Atomic force microscopy of insulin single crystals: direct visualization of molecules and crystal growth. Biophys J. 1996 Aug;71(2):1071–1078. doi: 10.1016/S0006-3495(96)79307-4. [DOI] [PMC free article] [PubMed] [Google Scholar]