Spanish to English Bus/Financial Real Estate

Solicitamos a usted otorgué escritura publica en su protocolo en la que se consigne el contrato de apertura de crédito simple con garantía hipotecaria..."

This is the header for a "carta de instruccion" for a loan for the purchase of a home in Mexico. I'm having problems with this sentence because I don't understand it.. some thing about a document recorded by a notary ... but I can't see where protocal comes into it. Anyway, I'm very confused.

Thanks so much for your help.