Design and synthesis of novel isoelectric buffers
| Title: | Design and synthesis of novel isoelectric buffers |
| Author: | Lalwani, Sanjiv Kumar Shankerdass, 1977- |
| Abstract: | Hydrolytically stable , low - and high -pI isoelectric hydrogel membranes were prepared from poly (vinyl alcohol ) (PVA ) as alternatives to polyacrylamide -based isoelectric membranes that hydrolyze in acidic and basic solutions . Low -pI membranes were made by attaching an isoelectric buffer of a welldefined pI value (such as iminodiacetic acid , IDA , aspartic acid , ASP or glutamic acid , GLU ) to the PVA backbone and crosslinking the PVA strands , in situ . The pH in these membranes does not change significantly with slight variations in the amount of isoelectric buffer that gets incorporated . The pI values of these membranes were pI is greater then 1 .7 but less then 2 .0 (IDAPVA ) , pI is greater then 2 .0 but less then 2 .6 (ASPPVA ) and pI was greater then 2 .6 but less then 3 .4 (GLUPVA ) .The membranes were used as anodic membranes in isoelectric trapping (IET ) experiments . Sugars , cyclodextrins (CDs ) , and certain polyhydroxy compounds have pKa values between 11 .5 and 14 . Thus , high -pI hydrogels were obtained by incorporating (i ) quaternary ammonium derivatives of Beta -CD (QCDPVA ) (ii ) quaternary ammonium groups and Beta -CD (CDQPVA ) and (iii ) quaternary ammonium groups alone (QPVA ) into the crosslinked PVA hydrogels . All three membranes had pI values greater than 11 and served as effective cathodic membranes for the IET of small ampholytic molecules and proteins . In pH -biased IET , proteins are collected into solutions of isoelectric buffers that set the pH to keep the proteins in a charged state affording high solubility and preventing precipitation . Thus , a series of isoelectric buffers (biasers ) with high buffering capacity , high conductivity , and pI values covering the useful pH 2 -10 range are needed . Two sets of such buffers were designed (i ) with pI values between the pKa values of two carboxylic acid groups and (ii ) with pI values between the pKa values of the conjugate acid form of two amine groups . Six of these buffers were synthesized and their synthesis was optimized . The products were obtained in their pure , isoelectric form and were extensively characterized . |
| URI: |
http : / /handle .tamu .edu /1969 .1 /3356
http : / /hdl .handle .net /1969 .1 /3356 |
| Date: | 2006-04-12 |
Citation
(August 2004).
Design and synthesis of novel isoelectric buffers.
Doctoral dissertation,
Texas A&M University. Available electronically from
http : / /handle .tamu .edu /1969 .1 /3356
.
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