Glutaraldehyde cross-link analogues from carbohydrates

The effectiveness of glutaraldehyde as protein cross-linker is unbeaten by any crosslinker known today. Surprisingly, no efforts have been made to improve the properties of glutaralclehyde via derivatisation. From the group of carbohydrates, periodate oxidised derivatives with cross-linking power have been reported. We demonstrate that these are based on the 1,5-dialdehyde structure, analogous with glutaraldehyde. Diglycolaldehyde and periodate oxidised carbohydrates containing this basic 1,5-dialdehyde moiety show excellent cross-linking properties. Although these cross-linkers are less reactive than glutaraldehyde, quantitative cross-linking is effected without undesired colouration and enzyme deactivation: effects often encountered with glutaraldehyde. These are the first results from an investigation in the use of carbohydrates for the alternative and inexpensive cross-linking of proteins.