Physics And Chemistry Basis Of Biotechnology - De Cuyper - tiera.ru

More documents

Recommendations

Info

Functional structure of the secretin receptor interaction with cholangiocytes [3 8]. Intravenous injections of secretin were used for years to evaluate the exocrine pancreatic function in human. The natural porcine secretin used first was contaminated by the neurohormone cholecystokininpancreozymin (CCK-PZ) that contracts vigorously the gallbladder; since the availability of essentially pure porcine secretin obtained from the Karolinska Institute, and later on from Kabi-Vitrum, the effect of secretin and CCK-PZ have been dissociated. The functional secretin-cholecystokinin test was performed by measuring fluid and enzyme secretion in duodenal aspirates. This was a good clinical test when performed by trained physicians. Its interest dropped however when retrograde cholangio-wirsungography was introduced as a routine endoscopic procedure : the visualisation of the pancreatic and the biliary tract was more helpful for the clinician than the functional tests. Furthermore, echography became the best non-invasive technique for gallbladder volume and contractility evaluation. Catheterisation of the main pancreatic duct with a balloon catheter allowed the analysis of pure pancreatic juice in response to secretin. This technique was however difficult to perform and was considered as an invasive one limited to experimental studies. More recently, the imaging of the pancreatic tree was possible by magnetic resonance cholangiopancreatography after secretin injection. This non-invasive technique will probably be in a near future the reference for pancreatic exploration. The systematic injection of secretin to patients suffering of gastrointestinal tract diseases will hopefully led to the discovery of secretin-linked pathologies (hypersecretory responses that could be due to constitutively active secretin receptors, absence of secretin response ...). Secretin, or preferably stable analogues - peptidic or non peptidic - could be of a great therapeutic value : repeated administration of secretin by inducing a high pancreatic flow rate might reduce the formation of pancreatic stones; secretin administered after fragmentation of pancreatic calculi by ultrasound bombardment will efficiently eliminate the stone fragments. Secretin is also a neuropeptide regulating tyrosine hydroxylase activity in PC 12 cells and in sympathetic ganglia [39]. It activates also adenylate cyclase in striatal neurons from embryonic mouse brain grown in cultures [40]. Its effect on adult rat brain occurs however at high concentrations only [41]. Recently, case reports of dramatic improvements of children suffering from autism were reported after secretin administration [42]. However, a recent double-blind study concluded that a single dose of human secretin was not an effective treatment for autism [43]. The use of more stable analogs with a facilitated penetration into the brain should be evaluated. How may the knowledge of the interactions between ligand and receptor contribute to the conception of peptidominetic ligands of potential therapeutic use ? Actually, most - if not all - peptidominetics have been discovered by chance (for instance the antibiotic erythromycin mimics the effect of the hormone Motilin by interacting with the motilin receptor) or by a systematic screening of large chemical libraries. This approach requires only an appropriate cellular model expressing the receptor of interest coupled to an easily detected effector system and the access to a large number of molecules. Another approach, based on the knowledge of the binding domain of the receptor is intellectually more rewarding but difficult : it requires a feed-back 173
P. Robberecht, M. Waelbroeck and N. Moguilevsky. interaction between receptor's modellers and biologists, but to start modelling, at least some firm structural data must be available. This is not the case for the G protein coupled receptors : the only available x-ray structure is that of bacteriorhodopsin that possesses seven transmembrane helices related to that of the receptors. The arrangement of the helices can be predicted in the receptor, but their fiability must still be validated. There is not data on the structure, or the folding of the aminoterminal extracellular domain of the receptor and as detailed in this review this domain is particularly important for ligand binding. Several laboratories try to produce sufficient amounts of the isolated aminoterminal domain to try a crystallisation of this large part of the receptor, but there is still no reported success in the literature. Acknowledgements This work was supported by an "Action de Recherche Concertée" from the Communautd Française de Belgique. References 1. Mutt, V. Secretin (1980) Isolation, Structure and Functions, in G.B. Jerzy Glass (eds.), Gastrointestinal Hormones, Raven Press, New York. pp 85-126. 2. Christophe, J., Svoboda, M., Dehaye, J.P., Winand, J., Vandermeers Piret, M.C., Vandermeers, A., Cauvin, A,, Gourlet, P., and Robberecht, P. (1989) The VIP/PHI/secretin/helodermin/helospectin/GRF family : structure-function relationship of the natural peptides, their precursors and synthetic analogues as tested in vitro on receptors and adenylate cyclase in a panel of tissue membranes, in J. Martinez (ed.), Peptide hormones as prohormones: Processing, Biological Activiv, Pharmacologv, Ellis Honvood Limited, Chichester pp. 21 1-243. 3. Zhou, Z.C., Gardner, J.D., and Jensen, R.T. (1987) Receptors for vasoactive intestinal peptide and secretin on guinea pig pancreatic acini, Peptides 8, 633-637. 4. Ishihara, T., Nakamura, S., Kaziro, Y., Takahashi, T., Takahashi, K., and Nagata, S. (1991) Molecular cloning and expression of a cDNA encoding the secretin receptor, EMEO. J. 10, 1635-1641. 5. Lin, H.Y., Harris, T.L., Flannery, M.S., Aruffo, A,, Kaji, E.H., Gorn, A,, Kolakowski, L.F. Jr, Lodish, H.F., and Goldring, S.R. (1991) Expression cloning of an adenylate cyclase-coupled calcitonin receptor, Science 254, 1022-1024. 6. Juppner, H., Abou Samra, A.B., Freeman, M., Kong, X.F., Schipani, E., Richards, J., Kolakowski, L.F. Jr, Hock, J., Potts, J.T. Jr, Kronenberg, H.M., et a.1. (1991) A G protein-linked receptor for parathyroid hormone and parathyroid hormone-related peptide, Science 254, 1024-1026. 7. Horn, F., Weare, J., Beukers, M.W., Horsch, S., Bairoch, A,, Chen, W., Edvardsen, O., Campagne, F., and Vriend, G. (1998)GPCRDB: an information system for G protein-coupled receptors, Nucleic Acids Res. 26, 215-279. 8. Svoboda, M., Tastenoy, M., De Neef, P., Delporte, C., Waelbroeck, M., and Robberecht, P. (1998) Molecular cloning and in vitro properties of the recombinant rabbit secretin receptor, Peptides 19, 1055-1062. 9. Paolo, E., De Neef, P., Moguilevsky, N., Petry, H., Cnudde, J., Bollen, A., Waelbroeck, M., and Robberecht, P. (1999) Properties of a recombinant human secretin receptor: a comparison with the rat and rabbit receptors, Pancreas 19, 5 1-55. 10. Patel, D.R., Kong, Y., and Sreedharan, S.P. (1995) Molecular cloning and expression of a human secretin receptor, Mol. Pharmacol. 47, 467-473. 174
Page 2 and 3:
PHYSICS AND CHEMISTRY BASIS OF BIOT
Page 4 and 5:
Physics and Chemistry Basis of Biot
Page 6 and 7:
EDITORS PREFACE At the end of the 2
Page 8 and 9:
TABLE OF CONTENTS EDITORS PREFACE .
Page 10 and 11:
4.3. Expression and functionality .
Page 12 and 13:
2 . Magnetically labelled antibodie
Page 14 and 15:
6.1. Instrumental characterisation
Page 16 and 17:
BIOMIMETIC MATERIALS SYNTHESIS Abst
Page 18 and 19:
Biomimetic materials synthesis cont
Page 20 and 21:
Biomimetic materials synthesis 3. I
Page 22 and 23:
Biomimetic materials synthesis The
Page 24 and 25:
Biomimetic materials synthesis 3.2.
Page 26 and 27:
Biomimetic materials synthesis 3.5.
Page 28 and 29:
Biomimetic materials synthesis In t
Page 30 and 31:
Biomimetic materials synthesis The
Page 32 and 33:
Biomimetic materials synthesis Othe
Page 34 and 35:
Biomimetic materials synthesis on s
Page 36 and 37:
Biomimetic materials synthesis form
Page 38 and 39:
Biomimetic materials synthesis poly
Page 40 and 41:
Biomimetic materials synthesis anal
Page 42 and 43:
Biomimetic materials synthesis Figu
Page 44 and 45:
Biomimetic materials synthesis Sinc
Page 46 and 47:
Biomimetic materials synthesis inte
Page 48 and 49:
Biomimetic materials synthesis 42.
Page 50 and 51:
Page 52 and 53:
Page 54 and 55:
DENDRIMERS: Chemical principles and
Page 56 and 57:
Dendrimers: Chemical principles and
Page 58 and 59:
Page 60 and 61:
Page 62 and 63:
Page 64 and 65:
Page 66 and 67:
Page 68 and 69:
Page 70 and 71:
Page 72 and 73:
Page 74 and 75:
Page 76 and 77:
Page 78 and 79:
RATIONAL DESIGN OF P450 ENZYMES FOR
Page 80 and 81:
Rational design of P450 enzymes for
Page 82 and 83:
Page 84 and 85:
Page 86 and 87:
Page 88 and 89:
Page 90 and 91:
Page 92 and 93:
Page 94 and 95:
Page 96 and 97:
Page 98 and 99:
Page 100 and 101:
Page 102 and 103:
Page 104 and 105:
Page 106 and 107:
Page 108 and 109:
Page 110 and 111:
Page 112 and 113:
AMPEROMETRIC ENZYME-BASED BIOSENSOR
Page 114 and 115:
Amperometric enzyme-based biosensor
Page 116 and 117:
Page 118 and 119:
Page 120 and 121:
Page 122 and 123:
Page 124 and 125:
Page 126 and 127:
Page 128 and 129:
Page 130 and 131: Amperometric enzyme-based biosensor
Page 138 and 139: SUPPORTED LIPID MEMBRANES FOR RECON
Page 140 and 141: Supported lipid membranes for recon
Page 174 and 175: FUNCTIONAL STRUCTURE OF THE SECRETI
Page 176 and 177: Functional structure of the secreti
Page 184 and 185: COLD-ADAPTED ENZYMES D. GEORLETTE,
Page 186 and 187: Cold-adapted enzymes enzyme activit
Page 188 and 189: Cold-adapted enzymes their high spe
Page 190 and 191: Cold-adapted enzymes flexibility of
Page 192 and 193: Cold-adapted enzymes Some recent wo
Page 194 and 195: Cold-adapted enzymes Figure 2. Acti
Page 196 and 197: Cold-adapted enzymes is not complet
Page 198 and 199: Cold-adapted enzymes 16. Gilichinsk
Page 200 and 201: Cold-adapted enzymes 58. Rina, M.,
Page 202 and 203: Cold-adapted enzymes 101. Yip, K. S
Page 204 and 205: MOLECULAR AND CELLULAR MAGNETIC RES
Page 206 and 207: Molecular and cellular magnetic res
Page 220 and 221: RADIOACTIVE MICROSPHERES FOR MEDICA
Page 222 and 223: Radioactive microspheres for medica
Page 230 and 231:
Radioactive microspheres for medica
Page 232 and 233:
Page 234 and 235:
Page 236 and 237:
Page 238 and 239:
Page 240 and 241:
Page 242 and 243:
Page 244 and 245:
Page 246 and 247:
Page 248 and 249:
Page 250 and 251:
Page 252 and 253:
Page 254 and 255:
Page 256 and 257:
RADIATION-INDUCED BIORADICALS: Phys
Page 258 and 259:
Radiation-induced bioradicals: phys
Page 260 and 261:
Page 262 and 263:
Page 264 and 265:
Page 266 and 267:
Page 268 and 269:
Page 270 and 271:
Page 272 and 273:
Page 274 and 275:
Page 276 and 277:
Page 278 and 279:
Page 280 and 281:
Page 282 and 283:
Page 284 and 285:
RADIATION-INDUCED BIORADICALS: Tech
Page 286 and 287:
Radiation-induced bioradicals: tech
Page 288 and 289:
Page 290 and 291:
Page 292 and 293:
Page 294 and 295:
Page 296 and 297:
Page 298 and 299:
Page 300 and 301:
References Radiation-induced biorad
Page 302 and 303:
Page 304 and 305:
Page 306 and 307:
Page 308 and 309:
Page 310 and 311:
Page 312 and 313:
AROMA MEASUREMENT: Recent developme
Page 314 and 315:
Aroma measurement: recent developme
Page 316 and 317:
Page 318 and 319:
Page 320 and 321:
Page 322 and 323:
Page 324 and 325:
Page 326 and 327:
Page 328 and 329:
Page 330 and 331:
Page 332 and 333:
Page 334 and 335:
62 63 64 65 66 67 68 69 70 71 72 73
Page 336 and 337:
INDEX albumin.... 122,151, 198, 206
Page 338 and 339:
frog embryo .......................
Page 340 and 341:
P-32 ..............................
show all

Physics And Chemistry Basis Of Biotechnology - De Cuyper - tiera.ru

Create successful ePaper yourself

Delete template?

Save as template?