Returns a JSON serializable represenation of a ``PeptideSequence``
        class instance. Use :func:`maspy.proteindb.PeptideSequence._fromJSON()`
        to generate a new ``PeptideSequence`` instance from the return value.

        :returns: a JSON serializable python object

def _reprJSON(self):
        """Returns a JSON serializable represenation of a ``PeptideSequence``
        class instance. Use :func:`maspy.proteindb.PeptideSequence._fromJSON()`
        to generate a new ``PeptideSequence`` instance from the return value.

        :returns: a JSON serializable python object
        """
        return {'__PepSeq__': [self.sequence, self.missedCleavage,
                               self.isUnique, list(self.proteins),
                               self.proteinPositions]}