The binding of heparin to type IV collagen: domain specificity with identification of peptide sequences from the α1(IV) and α2(IV) which preferentially bind heparin

Identification of a multifunctional, cell-binding peptide sequence from the a1(NC1) of type IV collagen.

“…We have also examined the binding of heparin to intact type IV collagen, the above-mentioned proteolytic domains and peptide sequences from these domains (both from the al[IV] and the a2[IV] chains). Previously three discrete amino acid sequences of type IV collagen were described that specifically bind to heparin and also inhibit the binding of heparin to type IV collagen (19). In the present report, we extend our earlier observations and describe additional functions of one heparin-binding peptide, peptide Hep-I.…”

“…Type IV collagen was isolated from the Engelbreth-Holm-Swarm (EHS) tu-mor, a noninvasive murine tumor (26) as described previously (19,30,36). The concentration of type IV collagen was determined by the method of Waddell (33,34).…”

“…The main (NC1) domain of type IV collagen was isolated by collagenase digestion of EHS-derived type IV collagen as described elsewhere (19,30,31). The concentration of isolated NC1 domain of type IV collagen was determined by the method of Lowry (22).…”

“…The major triple helical fragment of type IV collagen was isolated by a light digestion of EHS-derived type IV collagen with pepsin as reported elsewhere (16,19). The concentration of the triple helical, pepsin-derived fragment (which lacks the NCI domain) was determined by the method of Waddell (33,34).…”

“…Peptides were synthesized on a solid phase support resin according to the technique of Barany and Merrifield (2,19). The synthesized peptides were deprotected and released as reported previously (19). Peptides were checked for purity by HPLC, amino acid analysis and amino acid sequencing.…”